AcclimatedMoonCats(😺)

{{
  "language": "Solidity",
  "sources": {
    "MoonCatAcclimator.sol": {
      "content": "// SPDX-License-Identifier: GPL-3.0-only\r\npragma solidity ^0.7.3;\r\n\r\nimport \"./openzeppelin/contracts/token/ERC721/ERC721.sol\";\r\nimport \"@openzeppelin/contracts/token/ERC721/ERC721Holder.sol\";\r\nimport \"@openzeppelin/contracts/access/Ownable.sol\";\r\nimport \"@openzeppelin/contracts/utils/Pausable.sol\";\r\nimport \"./IERC998.sol\";\r\nimport \"./MoonCatOrderLookup.sol\";\r\n\r\n//        ##          ##\r\n//      ##  ##      ##  ##\r\n//      ##..  ######  ..##\r\n//    ####              ####\r\n//    ##                  ##\r\n//    ##    ()      ()    ##\r\n//    ##                  ##\r\n//    ##     \\  ##  /     ##\r\n//    ##      \\/  \\/      ##\r\n//      ##              ##\r\n//        ##############\r\n//\r\n//    #AcclimatedMoonCatsGlow\r\n//  https://mooncat.community/\r\n\r\n\r\n/**\r\n * @title MoonCat​Acclimator\r\n * @notice Accepts an original MoonCat and wraps it to present an ERC721- and ERC998-compliant asset\r\n * @notice Accepts a MoonCat wrapped with the older wrapping contract (at 0x7C40c3...) and re-wraps them\r\n * @notice Ownable by an admin address. Rights of the Owner are to pause and unpause the contract, and update metadata URL\r\n */\r\ncontract MoonCatAcclimator is\r\n    ERC721,\r\n    ERC721Holder,\r\n    Ownable,\r\n    Pausable,\r\n    IERC998ERC721TopDown,\r\n    IERC998ERC721TopDownEnumerable\r\n{\r\n    bytes32 private constant ERC998_MAGIC_VALUE = 0x00000000000000000000000000000000000000000000000000000000cd740db5;\r\n    bytes4 private constant _INTERFACE_ID_ERC998ERC721TopDown = 0x1efdf36a;\r\n\r\n    MoonCatOrderLookup public rescueOrderLookup;\r\n\r\n    MoonCatRescue MCR = MoonCatRescue(0x60cd862c9C687A9dE49aecdC3A99b74A4fc54aB6);\r\n    MoonCatsWrapped OLD_MCRW = MoonCatsWrapped(0x7C40c393DC0f283F318791d746d894DdD3693572);\r\n\r\n    constructor(string memory baseURI)\r\n        ERC721(unicode\"Acclimated​MoonCats\", unicode\"?\")\r\n        Ownable()\r\n    {\r\n        _registerInterface(_INTERFACE_ID_ERC998ERC721TopDown);\r\n        rescueOrderLookup = new MoonCatOrderLookup();\r\n        setBaseURI(baseURI);\r\n        _pause(); // Start in a paused state\r\n    }\r\n\r\n    function pause() public whenNotPaused onlyOwner {\r\n        _pause();\r\n    }\r\n    function unpause() public whenPaused onlyOwner {\r\n        _unpause();\r\n    }\r\n\r\n    /**\r\n     * @dev Emitted when `catId` token is wrapped into `tokenId`, owned by `owner`.\r\n     */\r\n    event MoonCatAcclimated(\r\n        uint256 tokenId,\r\n        address indexed owner\r\n    );\r\n\r\n    /**\r\n     * @dev Emitted when `catId` token is unwrapped from `tokenId`, owned by `owner`.\r\n     */\r\n    event MoonCatDeacclimated(\r\n        uint256 tokenId,\r\n        address indexed owner\r\n    );\r\n\r\n    /**\r\n     * @dev returns tokenId of newly minted wrapped MoonCat\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - Do not need to check if _msgSender() is MoonCat owner as the wrapped token is assigned to owner (even if that's not _msgSender())\r\n     * - Owner needs to call makeAdoptionOfferToAddress() in moonCatRescue first.\r\n     * Emits a {Transfer} ERC721 event.\r\n     * @param _rescueOrder the minting order of the MoonCat to wrap\r\n     * @return the ID (rescue order) of the minted token\r\n     */\r\n    function wrap(uint256 _rescueOrder) public returns (uint256) {\r\n        bytes5 catId = MCR.rescueOrder(_rescueOrder);\r\n        address _owner = MCR.catOwners(catId);\r\n        MCR.acceptAdoptionOffer(catId);\r\n        return _wrap(_owner, _rescueOrder);\r\n    }\r\n\r\n    /**\r\n     * @dev returns tokenId of newly minted wrapped MoonCat\r\n     *\r\n     * This method must not allow an adoption offer specifically to the new Wrapper address to be buy-able by anyone,\r\n     * because that is how the real owner sets up a manual wrapping of the MoonCat (where they don't really intend to sell).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - MoonCat at `_rescueOrder` must be offered for sale to any address.\r\n     * - Must have active makeAdoptionOffer() in moonCatRescue contract.\r\n     * Emits a {Transfer} and {MoonCatAcclimated} event.\r\n     * @param _rescueOrder the minting order of the MoonCat to wrap\r\n     * @return the ID (rescue order) of the minted token\r\n     */\r\n    function buyAndWrap(uint256 _rescueOrder) public payable returns (uint256) {\r\n        bytes5 catId = MCR.rescueOrder(_rescueOrder);\r\n        (bool exists, , , , address onlyOfferTo) = MCR.adoptionOffers(catId);\r\n        require(\r\n            onlyOfferTo == address(0) && exists,\r\n            \"That MoonCat is not for sale\"\r\n        );\r\n        MCR.acceptAdoptionOffer{value: msg.value}(catId);\r\n        return _wrap(_msgSender(), _rescueOrder);\r\n    }\r\n\r\n    /**\r\n     * @dev returns tokenId of burned unwrapped MoonCat\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - msgSender() must be owner.\r\n     * Emits a {Transfer} and {MoonCatDeacclimated} event.\r\n     * @param _tokenId the minting order of the MoonCat to unwrap\r\n     * @return the ID (rescue order) of the burned token\r\n     */\r\n    function unwrap(uint256 _tokenId) public returns (uint256) {\r\n        require(ownerOf(_tokenId) == _msgSender(), \"Not your MoonCat!\");\r\n        require(\r\n            super._exists(_tokenId),\r\n            \"That MoonCat is not wrapped in this contract\"\r\n        );\r\n        bytes5 catId = MCR.rescueOrder(_tokenId);\r\n        MCR.giveCat(catId, ownerOf(_tokenId));\r\n        _burn(_tokenId);\r\n        emit MoonCatDeacclimated(_tokenId, _msgSender());\r\n        return _tokenId;\r\n    }\r\n\r\n    /**\r\n     * @dev wraps MoonCat that was safeTransferFrom() the old MoonCat wrapper directly in one transaction\r\n     *\r\n     * Requirements:\r\n     * - Owner of old wrapped MoonCat must include the rescueOrder in the calldata as a bytes32\r\n     * Emits a {Transfer} and {MoonCatAcclimated} event.\r\n     * @param _to the address that is to be the owner of the newly-wrapped token\r\n     * @param _oldTokenID the ID of the token in the other wrapping contract\r\n     * @param _rescueOrder the minting order of the MoonCat being wrapped\r\n     * @return the ID (rescue order) of the minted token\r\n     */\r\n    function _wrapOnSafeTransferFromReceipt(\r\n        address _to,\r\n        uint256 _oldTokenID,\r\n        uint256 _rescueOrder\r\n    ) internal returns (uint256) {\r\n        if (\r\n            MCR.rescueOrder(_rescueOrder) !=\r\n            OLD_MCRW._tokenIDToCatID(_oldTokenID)\r\n        ) {\r\n            // Look up rescue order in Lookup contract\r\n            require(\r\n                rescueOrderLookup.oldTokenIdExists(_oldTokenID),\r\n                \"Unable to determine proper rescueOrder for this old token ID\"\r\n            );\r\n            _rescueOrder = rescueOrderLookup.oldTokenIdToRescueOrder(\r\n                _oldTokenID\r\n            );\r\n            require(\r\n                MCR.rescueOrder(_rescueOrder) ==\r\n                    OLD_MCRW._tokenIDToCatID(_oldTokenID),\r\n                \"_oldTokenID and _rescueOrder do not match same catID\"\r\n            );\r\n        }\r\n        OLD_MCRW.unwrap(_oldTokenID);\r\n        return _wrap(_to, _rescueOrder);\r\n    }\r\n\r\n    /**\r\n     * @dev wraps an unwrapped MoonCat\r\n     *\r\n     * notes:\r\n     * Emits a {Transfer} and {MoonCatAcclimated} event.\r\n     * @param _owner the address that should be the new owner of the newly-created token\r\n     * @param _tokenId the ID of the token to create (rescue order of the MoonCat)\r\n     * @return the ID (rescue order) of the minted token\r\n     */\r\n    function _wrap(address _owner, uint256 _tokenId)\r\n        internal\r\n        returns (uint256)\r\n    {\r\n        require(!paused(), \"Attempted wrap while paused\");\r\n        _mint(_owner, _tokenId);\r\n        emit MoonCatAcclimated(_tokenId, _msgSender());\r\n        return _tokenId;\r\n    }\r\n\r\n    /**\r\n     * @dev Always returns `IERC721Receiver.onERC721Received.selector`\r\n     *\r\n     * This function handles both automatic rewrapping of old-wrapped MoonCats, and assigning ERC721 tokens as \"child assets\"\r\n     * of MoonCats already wrapped with this contract.\r\n     *\r\n     * If the incoming token is an old-wrapped Mooncat, the `_data` variable is structured as\r\n     * the first 32 bytes are the rescue order of the transferred MoonCat, subsequent 20 bytes\r\n     * are the new owner's address. If the rescue order is not supplied, the `_oldTokenId` is\r\n     * looked up in the {MoonCatOrderLookup} contract. If a new owner's address is not\r\n     * supplied, the new owner will be assigned as the `_from` sender.\r\n     * Emits a {Transfer} and {MoonCatAcclimated} event.\r\n     *\r\n     * If the incoming token is any other type of ERC721, the `_data` variable is structured as\r\n     * the first 32 bytes are the token ID (rescue order) of the MoonCat that is to receive that assest.\r\n     * Emits a {ReceivedChild} event.\r\n     *\r\n     * @param _operator the _msgSender of the transaction\r\n     * @param _from the address of the former owner of the incoming token\r\n     * @param _oldTokenId the ID of the incoming token\r\n     * @param _data additional metdata\r\n     */\r\n    function onERC721Received(\r\n        address _operator,\r\n        address _from,\r\n        uint256 _oldTokenId,\r\n        bytes calldata _data\r\n    ) public override(ERC721Holder, IERC998ERC721TopDown) returns (bytes4) {\r\n        // Using msg.sender here instead of _operator because we want to know the most recent transaction source,\r\n        // not the start of the chain\r\n        if (msg.sender == address(0x7C40c393DC0f283F318791d746d894DdD3693572)) {\r\n            // This is a Wrapped MoonCat incoming. Don't make it a child, instead unwrap and re-wrap it\r\n\r\n            // Who should own this MoonCat after wrapping?\r\n            address _to =\r\n                (_data.length >= 32 + 20 && bytesToAddress(_data, 32) != address(0))\r\n                    ? bytesToAddress(_data, 32)\r\n                    : _from;\r\n            require(\r\n                _to != address(0) && _to != address(this),\r\n                \"Invalid destination owner specified\"\r\n            );\r\n\r\n            _wrapOnSafeTransferFromReceipt(\r\n                _to,\r\n                _oldTokenId,\r\n                (_data.length >= 32) ? toUint256(_data, 0) : 0\r\n            );\r\n            return ERC721Holder.onERC721Received(_operator, _from, _oldTokenId, _data);\r\n        }\r\n\r\n        // Otherwise, handle as ERC998 Child incoming\r\n        require(_data.length > 0, \"_data must contain the uint256 tokenId to transfer the child token to\");\r\n        // convert up to 32 bytes of_data to uint256, owner NFT tokenId passed as uint in bytes\r\n        uint256 tokenId;\r\n        assembly {tokenId := calldataload(164)}\r\n        if (_data.length < 32) {\r\n            tokenId = tokenId >> 256 - _data.length * 8;\r\n        }\r\n        _receiveChild(_from, tokenId, msg.sender, _oldTokenId);\r\n        require(ERC721(msg.sender).ownerOf(_oldTokenId) != address(0), \"Child token not owned\");\r\n        return ERC721Holder.onERC721Received(_operator, _from, _oldTokenId, _data);\r\n    }\r\n\r\n    /**\r\n     * @dev sets the base URI\r\n     *\r\n     * notes:\r\n     * - only callable by the contract owner\r\n     */\r\n    function setBaseURI(string memory _newBaseURI) public onlyOwner {\r\n        _setBaseURI(_newBaseURI);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-balanceOf}.\r\n     * This contract returns the locally-wrapped token count as well as old-wrapped MoonCats\r\n     * that are mapped in the {MoonCatOrderLookup} contract.\r\n     */\r\n    function balanceOf(address _owner) public view override returns (uint256) {\r\n        return\r\n            super.balanceOf(_owner) +\r\n            rescueOrderLookup.entriesPerAddress(_owner);\r\n    }\r\n\r\n    /**\r\n    * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.\r\n     * This contract enumerates the locally-wrapped token count as well as old-wrapped MoonCats\r\n     * that are mapped in the {MoonCatOrderLookup} contract.\r\n    */\r\n    function tokenOfOwnerByIndex(address _owner, uint256 _index)\r\n        public\r\n        view\r\n        override\r\n        returns (uint256)\r\n    {\r\n        uint256 localBalance = super.balanceOf(_owner);\r\n        if (_index < localBalance) {\r\n            // This index is in the range of tokens owned by that address here in this contract\r\n            return super.tokenOfOwnerByIndex(_owner, _index);\r\n        }\r\n\r\n        // Looking to enumerate a token that's mapped to the old wrapping contract\r\n        uint16 countFound = 0;\r\n        for (uint256 i = 0; i < OLD_MCRW.balanceOf(_owner); i++) {\r\n            uint256 oldTokenId = OLD_MCRW.tokenOfOwnerByIndex(_owner, i);\r\n            if (rescueOrderLookup.oldTokenIdExists(oldTokenId)) {\r\n                countFound++;\r\n                if (countFound == _index - localBalance + 1) {\r\n                    return\r\n                        rescueOrderLookup.oldTokenIdToRescueOrder(oldTokenId);\r\n                }\r\n            }\r\n        }\r\n        revert(\"Cannot find token ID for that index\");\r\n    }\r\n\r\n    /**\r\n    * @dev See {IERC721-ownerOf}.\r\n    */\r\n    function ownerOf(uint256 _tokenId) public view override returns (address) {\r\n        if (super._exists(_tokenId)) {\r\n            return super.ownerOf(_tokenId);\r\n        }\r\n\r\n        // Check other wrapper\r\n\r\n        // First see if we're dealing with the MoonCat that was the zeroth-wrapped MoonCat in other wrapper\r\n        bytes5 thisMoonCatID = MCR.rescueOrder(_tokenId);\r\n        if (thisMoonCatID == OLD_MCRW._tokenIDToCatID(0)) {\r\n            return OLD_MCRW.ownerOf(0);\r\n        }\r\n        uint256 otherID = OLD_MCRW._catIDToTokenID(thisMoonCatID);\r\n        // We're not dealing with the zeroth-wrapped MoonCat, so a zero here is an indication they don't exist\r\n        require(otherID > 0, \"That MoonCat is not wrapped\");\r\n        return OLD_MCRW.ownerOf(otherID);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-isApprovedForAll}.\r\n     */\r\n    function isApprovedForAll(address _owner, address _operator)\r\n        public\r\n        view\r\n        virtual\r\n        override\r\n        returns (bool)\r\n    {\r\n        return\r\n            rescueOrderLookup.entriesPerAddress(_owner) == 0\r\n                ? super.isApprovedForAll(_owner, _operator)\r\n                : super.isApprovedForAll(_owner, _operator) &&\r\n                    OLD_MCRW.isApprovedForAll(_owner, address(this));\r\n    }\r\n\r\n    /**\r\n     * @dev See {ERC721-_isApprovedOrOwner}.\r\n     */\r\n    function _isApprovedOrOwner(address _spender, uint256 _tokenId)\r\n        internal\r\n        view\r\n        override\r\n        returns (bool)\r\n    {\r\n        require(\r\n            _exists(_tokenId),\r\n            \"ERC721: operator query for nonexistent token\"\r\n        );\r\n        // Differs here from OpenZeppelin standard:\r\n        // Calls `ownerOf` instead of `ERC721.ownerOf`\r\n        address _owner = ownerOf(_tokenId);\r\n        return (_spender == _owner ||\r\n            getApproved(_tokenId) == _spender ||\r\n            ERC721.isApprovedForAll(_owner, _spender));\r\n    }\r\n\r\n    /**\r\n     * @dev See {ERC721-approve}.\r\n     */\r\n    function approve(address _to, uint256 _tokenId) public override {\r\n        address _owner = ownerOf(_tokenId);\r\n        require(_to != _owner, \"ERC721: approval to current owner\");\r\n        // Differs here from OpenZeppelin standard:\r\n        // Calls `isApprovedForAll` instead of `ERC721.isApprovedForAll`\r\n        require(\r\n            _msgSender() == _owner || isApprovedForAll(_owner, _msgSender()),\r\n            \"ERC721: approve caller is not owner nor approved for all\"\r\n        );\r\n\r\n        _approve(_to, _tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev rewrap several MoonCats from the old wrapper at once\r\n     * Owner needs to call setApprovalForAll in old wrapper first.\r\n     * @param _rescueOrders an array of MoonCats, identified by rescue order, to rewrap\r\n     * @param _oldTokenIds an array holding the corresponding token ID\r\n     *        in the old wrapper for each MoonCat to be rewrapped\r\n     */\r\n    function batchReWrap(\r\n        uint256[] memory _rescueOrders,\r\n        uint256[] memory _oldTokenIds\r\n    ) public {\r\n        for (uint16 i = 0; i < _rescueOrders.length; i++) {\r\n            address _owner = OLD_MCRW.ownerOf(_oldTokenIds[i]);\r\n            OLD_MCRW.safeTransferFrom(\r\n                _owner,\r\n                address(this),\r\n                _oldTokenIds[i],\r\n                abi.encodePacked(\r\n                    uintToBytes(_rescueOrders[i]),\r\n                    addressToBytes(_owner)\r\n                )\r\n            );\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev Take a list of unwrapped MoonCat rescue orders and wrap them.\r\n     * @param _rescueOrders an array of MoonCats, identified by rescue order, to rewrap\r\n     */\r\n    function batchWrap(uint256[] memory _rescueOrders) public {\r\n        for (uint16 i = 0; i < _rescueOrders.length; i++) {\r\n            wrap(_rescueOrders[i]);\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev Take a list of MoonCats wrapped in this contract and unwrap them.\r\n     * @param _rescueOrders an array of MoonCats, identified by rescue order, to unwrap\r\n     */\r\n    function batchUnwrap(uint256[] memory _rescueOrders) public {\r\n        for (uint16 i = 0; i < _rescueOrders.length; i++) {\r\n            unwrap(_rescueOrders[i]);\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev See {ERC721-_transfer}.\r\n     * If the token being transferred exists in this contract, the standard ERC721 logic is used.\r\n     * If the token does not exist in this contract, look it up in the old wrapping contract,\r\n     * and attempt to wrap-then-transfer it.\r\n     */\r\n    function _transfer(\r\n        address _from,\r\n        address _to,\r\n        uint256 _tokenId\r\n    ) internal override {\r\n        if (super._exists(_tokenId)) {\r\n            return super._transfer(_from, _to, _tokenId);\r\n        }\r\n\r\n        require(_to != address(0), \"ERC721: transfer to the zero address\");\r\n\r\n        if (_to == address(this)) {\r\n            // Sending the token to be owned by this contract? That's not what they meant; make it owned by the original owner after re-wrapping\r\n            _to = _from;\r\n        }\r\n        uint256 oldTokenId =\r\n            OLD_MCRW._catIDToTokenID(MCR.rescueOrder(_tokenId));\r\n        OLD_MCRW.safeTransferFrom(\r\n            _from,\r\n            address(this),\r\n            oldTokenId,\r\n            abi.encodePacked(uintToBytes(_tokenId), addressToBytes(_to))\r\n        );\r\n        rescueOrderLookup.removeEntry(oldTokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev See {ERC721-_exists}.\r\n     * If the token being queried exists in this contract, the standard ERC721 logic is used.\r\n     * If the token does not exist in this contract, look it up in the old wrapping contract,\r\n     * and see if it exists there.\r\n     */\r\n    function _exists(uint256 _tokenId) internal view override returns (bool) {\r\n        if (super._exists(_tokenId)) {\r\n            return true;\r\n        }\r\n\r\n        // Check if exists in old wrapping contract\r\n        bytes5 realMoonCatZero = OLD_MCRW._tokenIDToCatID(0);\r\n        bytes5 thisMoonCatID = MCR.rescueOrder(_tokenId);\r\n        if (thisMoonCatID == realMoonCatZero) {\r\n            return true;\r\n        }\r\n\r\n        return OLD_MCRW._catIDToTokenID(thisMoonCatID) != 0;\r\n    }\r\n\r\n    ///// ERC998 /////\r\n    using EnumerableSet for EnumerableSet.UintSet;\r\n    using EnumerableSet for EnumerableSet.AddressSet;\r\n\r\n    /// @dev mapping of local token IDs, and which addresses they own children at.\r\n    /// tokenId => child contract\r\n    mapping(uint256 => EnumerableSet.AddressSet) private childContracts;\r\n\r\n    /// @dev mapping of local token IDs, addresses they own children at, and IDs of the specific child tokens\r\n    /// tokenId => (child address => array of child tokens)\r\n    mapping(uint256 => mapping(address => EnumerableSet.UintSet)) private childTokens;\r\n\r\n    /// @dev mapping of addresses of child tokens, the specific child token IDs, and which local token owns them\r\n    /// child address => childId => tokenId\r\n    mapping(address => mapping(uint256 => uint256)) internal childTokenOwner;\r\n    uint8 constant TOKEN_OWNER_OFFSET = 10;\r\n\r\n    /**\r\n     * @dev a token has been transferred to this contract mark which local token is to now own it\r\n     * Emits a {ReceivedChild} event.\r\n     *\r\n     * @param _from the address who sent the token to this contract\r\n     * @param _tokenId the local token ID that is to be the parent\r\n     * @param _childContract the address of the child token's contract\r\n     * @param _childTokenId the ID value of teh incoming child token\r\n     */\r\n    function _receiveChild(address _from, uint256 _tokenId, address _childContract, uint256 _childTokenId) private {\r\n        require(!paused(), \"Child received while paused\");\r\n        require(super._exists(_tokenId), \"That MoonCat is not wrapped in this contract\");\r\n        require(childTokens[_tokenId][_childContract].contains(_childTokenId) == false, \"Cannot receive child token because it has already been received\");\r\n        childContracts[_tokenId].add(_childContract);\r\n        childTokens[_tokenId][_childContract].add(_childTokenId);\r\n        childTokenOwner[_childContract][_childTokenId] = _tokenId + TOKEN_OWNER_OFFSET;\r\n        emit ReceivedChild(_from, _tokenId, _childContract, _childTokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDown-getChild}.\r\n     */\r\n    function getChild(\r\n        address _from,\r\n        uint256 _tokenId,\r\n        address _childContract,\r\n        uint256 _childTokenId\r\n    ) public override {\r\n        _receiveChild(_from, _tokenId, _childContract, _childTokenId);\r\n        IERC721(_childContract).transferFrom(_from, address(this), _childTokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev Given a child address/ID that is owned by some token in this contract, return that owning token's owner\r\n     * @param _childContract the address of the child asset being queried\r\n     * @param _childTokenId the specific ID of the child asset being queried\r\n     * @return parentTokenOwner the address of the owner of that child's parent asset\r\n     * @return parentTokenId the local token ID that is the parent of that child asset\r\n     */\r\n    function _ownerOfChild(address _childContract, uint256 _childTokenId) internal view returns (address parentTokenOwner, uint256 parentTokenId) {\r\n        parentTokenId = childTokenOwner[_childContract][_childTokenId];\r\n        require(parentTokenId > 0, \"That child is not owned by a token in this contract\");\r\n        return (ownerOf(parentTokenId - TOKEN_OWNER_OFFSET), parentTokenId - TOKEN_OWNER_OFFSET);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDown-ownerOfChild}.\r\n     */\r\n    function ownerOfChild(address _childContract, uint256 _childTokenId)\r\n        public\r\n        override\r\n        view\r\n        returns (bytes32 parentTokenOwner, uint256 parentTokenId)\r\n    {\r\n        parentTokenId = childTokenOwner[_childContract][_childTokenId];\r\n        require(parentTokenId > 0, \"That child is not owned by a token in this contract\");\r\n        return (ERC998_MAGIC_VALUE << 224 | bytes32(uint256(ownerOf(parentTokenId - TOKEN_OWNER_OFFSET))), parentTokenId - TOKEN_OWNER_OFFSET);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDown-rootOwnerOf}.\r\n     */\r\n    function rootOwnerOf(uint256 _tokenId)\r\n        public\r\n        override\r\n        view\r\n        returns (bytes32 rootOwner)\r\n    {\r\n        return rootOwnerOfChild(address(0), _tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDown-rootOwnerOfChild}.\r\n     */\r\n    function rootOwnerOfChild(address _childContract, uint256 _childTokenId)\r\n        public\r\n        override\r\n        view\r\n        returns (bytes32 rootOwner)\r\n    {\r\n        address rootOwnerAddress;\r\n        if (_childContract != address(0)) {\r\n            (rootOwnerAddress, _childTokenId) = _ownerOfChild(_childContract, _childTokenId);\r\n        } else {\r\n            rootOwnerAddress = ownerOf(_childTokenId);\r\n        }\r\n        // Case 1: Token owner is this contract and token.\r\n        while (rootOwnerAddress == address(this)) {\r\n            (rootOwnerAddress, _childTokenId) = _ownerOfChild(rootOwnerAddress, _childTokenId);\r\n        }\r\n\r\n        (bool callSuccess, bytes memory data) = rootOwnerAddress.staticcall(abi.encodeWithSelector(0xed81cdda, address(this), _childTokenId));\r\n        if (data.length != 0) {\r\n            rootOwner = abi.decode(data, (bytes32));\r\n        }\r\n\r\n        if(callSuccess == true && rootOwner >> 224 == ERC998_MAGIC_VALUE) {\r\n            // Case 2: Token owner is other top-down composable\r\n            return rootOwner;\r\n        }\r\n        else {\r\n            // Case 3: Token owner is other contract\r\n            // Or\r\n            // Case 4: Token owner is user\r\n            return ERC998_MAGIC_VALUE << 224 | bytes32(uint256(rootOwnerAddress));\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev remove internal records linking a given child to a given parent\r\n     * @param _tokenId the local token ID that is the parent of the child asset\r\n     * @param _childContract the address of the child asset to remove\r\n     * @param _childTokenId the specific ID representing the child asset to be removed\r\n     */\r\n    function _removeChild(uint256 _tokenId, address _childContract, uint256 _childTokenId) private {\r\n        require(\r\n            childTokens[_tokenId][_childContract].contains(_childTokenId),\r\n            \"Child token not owned by token\"\r\n        );\r\n\r\n        // remove child token\r\n        childTokens[_tokenId][_childContract].remove(_childTokenId);\r\n        delete childTokenOwner[_childContract][_childTokenId];\r\n\r\n        // remove contract\r\n        if (childTokens[_tokenId][_childContract].length() == 0) {\r\n            childContracts[_tokenId].remove(_childContract);\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev check permissions are correct for a transfer of a child asset\r\n     * @param _fromTokenId the local ID of the token that is the parent\r\n     * @param _to the address this child token is being transferred to\r\n     * @param _childContract the address of the child asset's contract\r\n     * @param _childTokenId the specific ID for the child asset being transferred\r\n     */\r\n    function _checkTransferChild(\r\n        uint256 _fromTokenId,\r\n        address _to,\r\n        address _childContract,\r\n        uint256 _childTokenId\r\n    ) private view {\r\n        require(!paused(), \"Child transfer while paused\");\r\n        uint256 tokenId = childTokenOwner[_childContract][_childTokenId];\r\n        require(tokenId > 0, \"Child asset is not owned by a token in this contract\");\r\n        tokenId -= TOKEN_OWNER_OFFSET;\r\n        require(tokenId == _fromTokenId, \"That MoonCat does not own that asset\");\r\n        require(_to != address(0), \"Transfer to zero address\");\r\n        address rootOwner = address(uint160(uint256(rootOwnerOf(_fromTokenId))));\r\n        require(\r\n            _msgSender() == rootOwner || getApproved(_fromTokenId) == _msgSender() || ERC721.isApprovedForAll(rootOwner, _msgSender()),\r\n            \"Not allowed to transfer child assets of that MoonCat\"\r\n        );\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDown-safeTransferChild}.\r\n     */\r\n    function safeTransferChild(\r\n        uint256 _fromTokenId,\r\n        address _to,\r\n        address _childContract,\r\n        uint256 _childTokenId\r\n    ) public override {\r\n        _checkTransferChild(_fromTokenId, _to, _childContract, _childTokenId);\r\n        _removeChild(_fromTokenId, _childContract, _childTokenId);\r\n        ERC721(_childContract).safeTransferFrom(address(this), _to, _childTokenId);\r\n        emit TransferChild(_fromTokenId, _to, _childContract, _childTokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDown-safeTransferChild}.\r\n     */\r\n    function safeTransferChild(\r\n        uint256 _fromTokenId,\r\n        address _to,\r\n        address _childContract,\r\n        uint256 _childTokenId,\r\n        bytes calldata _data\r\n    ) public override {\r\n        _checkTransferChild(_fromTokenId, _to, _childContract, _childTokenId);\r\n        _removeChild(_fromTokenId, _childContract, _childTokenId);\r\n        ERC721(_childContract).safeTransferFrom(address(this), _to, _childTokenId, _data);\r\n        emit TransferChild(_fromTokenId, _to, _childContract, _childTokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDown-transferChild}.\r\n     */\r\n    function transferChild(\r\n        uint256 _fromTokenId,\r\n        address _to,\r\n        address _childContract,\r\n        uint256 _childTokenId\r\n    ) public override {\r\n        _checkTransferChild(_fromTokenId, _to, _childContract, _childTokenId);\r\n        _removeChild(_fromTokenId, _childContract, _childTokenId);\r\n        //this is here to be compatible with cryptokitties and other old contracts that require being owner and approved\r\n        // before transferring.\r\n        //does not work with current standard which does not allow approving self, so we must let it fail in that case.\r\n        //0x095ea7b3 == \"approve(address,uint256)\"\r\n        (bool success, bytes memory data) = _childContract.call(abi.encodeWithSelector(0x095ea7b3, this, _childTokenId));\r\n        require(\r\n            success && (data.length == 0 || abi.decode(data, (bool))),\r\n            'Failed to Approve'\r\n        );\r\n        ERC721(_childContract).transferFrom(address(this), _to, _childTokenId);\r\n        emit TransferChild(_fromTokenId, _to, _childContract, _childTokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDown-transferChildToParent}.\r\n     */\r\n    function transferChildToParent(\r\n        uint256 _fromTokenId,\r\n        address _toContract,\r\n        uint256 _toTokenId,\r\n        address _childContract,\r\n        uint256 _childTokenId,\r\n        bytes calldata _data\r\n    ) public override {\r\n        _checkTransferChild(_fromTokenId, _toContract, _childContract, _childTokenId);\r\n        _removeChild(_fromTokenId, _childContract, _childTokenId);\r\n        IERC998ERC721BottomUp(_childContract).transferToParent(address(this), _toContract, _toTokenId, _childTokenId, _data);\r\n        emit TransferChild(_fromTokenId, _toContract, _childContract, _childTokenId);\r\n    }\r\n\r\n    ///// ERC998 Enumerable\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDownEnumerable-totalChildContracts}.\r\n     */\r\n    function totalChildContracts(uint256 _tokenId)\r\n        external\r\n        override\r\n        view\r\n        returns (uint256)\r\n    {\r\n        return childContracts[_tokenId].length();\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDownEnumerable-childContractByIndex}.\r\n     */\r\n    function childContractByIndex(uint256 _tokenId, uint256 _index)\r\n        external\r\n        override\r\n        view\r\n        returns (address childContract)\r\n    {\r\n        return childContracts[_tokenId].at(_index);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDownEnumerable-totalChildTokens}.\r\n     */\r\n    function totalChildTokens(uint256 _tokenId, address _childContract) external override view returns (uint256) {\r\n        return childTokens[_tokenId][_childContract].length();\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC998ERC721TopDownEnumerable-childTokenByIndex}.\r\n     */\r\n    function childTokenByIndex(uint256 _tokenId, address _childContract, uint256 _index) external override view returns (uint256 childTokenId) {\r\n        return childTokens[_tokenId][_childContract].at(_index);\r\n    }\r\n}\r\n\r\n// UTILITIES\r\n\r\n/**\r\n * @dev converts bytes (which is at least 32 bytes long) to uint256\r\n */\r\nfunction toUint256(bytes memory _bytes, uint256 _start) pure returns (uint256) {\r\n    require(_start + 32 >= _start, \"toUint256_overflow\");\r\n    require(_bytes.length >= _start + 32, \"toUint256_outOfBounds\");\r\n    uint256 tempUint;\r\n\r\n    assembly {\r\n        tempUint := mload(add(add(_bytes, 0x20), _start))\r\n    }\r\n\r\n    return tempUint;\r\n}\r\n\r\n/**\r\n * @dev converts uint256 to a bytes(32) object\r\n */\r\nfunction uintToBytes(uint256 x) pure returns (bytes memory b) {\r\n    b = new bytes(32);\r\n    assembly {\r\n        mstore(add(b, 32), x)\r\n    }\r\n}\r\n\r\n/**\r\n * @dev converts bytes (which is at least 20 bytes long) to address\r\n */\r\nfunction bytesToAddress(bytes memory bys, uint256 _start)\r\n    pure\r\n    returns (address addr)\r\n{\r\n    assembly {\r\n        addr := mload(add(add(bys, 20), _start))\r\n    }\r\n}\r\n\r\n/**\r\n * @dev converts address to a bytes(32) object\r\n */\r\nfunction addressToBytes(address a) pure returns (bytes memory) {\r\n    return abi.encodePacked(a);\r\n}\r\n"
    },
    "openzeppelin/contracts/token/ERC721/ERC721.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\nimport \"@openzeppelin/contracts/utils/Context.sol\";\r\nimport \"@openzeppelin/contracts/token/ERC721/IERC721.sol\";\r\nimport \"@openzeppelin/contracts/token/ERC721/IERC721Metadata.sol\";\r\nimport \"@openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol\";\r\nimport \"@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\";\r\nimport \"@openzeppelin/contracts/introspection/ERC165.sol\";\r\nimport \"@openzeppelin/contracts/math/SafeMath.sol\";\r\nimport \"@openzeppelin/contracts/utils/Address.sol\";\r\nimport \"@openzeppelin/contracts/utils/EnumerableSet.sol\";\r\nimport \"@openzeppelin/contracts/utils/EnumerableMap.sol\";\r\nimport \"@openzeppelin/contracts/utils/Strings.sol\";\r\n\r\n/**\r\n * @title ERC721 Non-Fungible Token Standard basic implementation\r\n * @dev see https://eips.ethereum.org/EIPS/eip-721\r\n */\r\ncontract ERC721 is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable {\r\n    using SafeMath for uint256;\r\n    using Address for address;\r\n    using EnumerableSet for EnumerableSet.UintSet;\r\n    using EnumerableMap for EnumerableMap.UintToAddressMap;\r\n    using Strings for uint256;\r\n\r\n    // Equals to `bytes4(keccak256(\"onERC721Received(address,address,uint256,bytes)\"))`\r\n    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`\r\n    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;\r\n\r\n    // Mapping from holder address to their (enumerable) set of owned tokens\r\n    mapping (address => EnumerableSet.UintSet) private _holderTokens;\r\n\r\n    // Enumerable mapping from token ids to their owners\r\n    EnumerableMap.UintToAddressMap private _tokenOwners;\r\n\r\n    // Mapping from token ID to approved address\r\n    mapping (uint256 => address) private _tokenApprovals;\r\n\r\n    // Mapping from owner to operator approvals\r\n    mapping (address => mapping (address => bool)) private _operatorApprovals;\r\n\r\n    // Token name\r\n    string private _name;\r\n\r\n    // Token symbol\r\n    string private _symbol;\r\n\r\n    // Optional mapping for token URIs\r\n    mapping (uint256 => string) private _tokenURIs;\r\n\r\n    // Base URI\r\n    string private _baseURI;\r\n\r\n    /*\r\n     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231\r\n     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e\r\n     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3\r\n     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc\r\n     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465\r\n     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5\r\n     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd\r\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e\r\n     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde\r\n     *\r\n     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^\r\n     *        0xa22cb465 ^ 0xe985e9c5 ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd\r\n     */\r\n    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;\r\n\r\n    /*\r\n     *     bytes4(keccak256('name()')) == 0x06fdde03\r\n     *     bytes4(keccak256('symbol()')) == 0x95d89b41\r\n     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd\r\n     *\r\n     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f\r\n     */\r\n    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;\r\n\r\n    /*\r\n     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd\r\n     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59\r\n     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7\r\n     *\r\n     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63\r\n     */\r\n    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;\r\n\r\n    /**\r\n     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.\r\n     */\r\n    constructor (string memory name_, string memory symbol_) public {\r\n        _name = name_;\r\n        _symbol = symbol_;\r\n\r\n        // register the supported interfaces to conform to ERC721 via ERC165\r\n        _registerInterface(_INTERFACE_ID_ERC721);\r\n        _registerInterface(_INTERFACE_ID_ERC721_METADATA);\r\n        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-balanceOf}.\r\n     */\r\n    function balanceOf(address owner) public view virtual override returns (uint256) {\r\n        require(owner != address(0), \"ERC721: balance query for the zero address\");\r\n        return _holderTokens[owner].length();\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-ownerOf}.\r\n     */\r\n    function ownerOf(uint256 tokenId) public view virtual override returns (address) {\r\n        return _tokenOwners.get(tokenId, \"ERC721: owner query for nonexistent token\");\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721Metadata-name}.\r\n     */\r\n    function name() public view virtual override returns (string memory) {\r\n        return _name;\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721Metadata-symbol}.\r\n     */\r\n    function symbol() public view virtual override returns (string memory) {\r\n        return _symbol;\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721Metadata-tokenURI}.\r\n     */\r\n    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {\r\n        require(_exists(tokenId), \"ERC721Metadata: URI query for nonexistent token\");\r\n\r\n        string memory _tokenURI = _tokenURIs[tokenId];\r\n        string memory base = baseURI();\r\n\r\n        // If there is no base URI, return the token URI.\r\n        if (bytes(base).length == 0) {\r\n            return _tokenURI;\r\n        }\r\n        // If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).\r\n        if (bytes(_tokenURI).length > 0) {\r\n            return string(abi.encodePacked(base, _tokenURI));\r\n        }\r\n        // If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.\r\n        return string(abi.encodePacked(base, tokenId.toString()));\r\n    }\r\n\r\n    /**\r\n    * @dev Returns the base URI set via {_setBaseURI}. This will be\r\n    * automatically added as a prefix in {tokenURI} to each token's URI, or\r\n    * to the token ID if no specific URI is set for that token ID.\r\n    */\r\n    function baseURI() public view virtual returns (string memory) {\r\n        return _baseURI;\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.\r\n     */\r\n    function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {\r\n        return _holderTokens[owner].at(index);\r\n    }\r\n\r\n    /**\r\n    * @dev Return an array of all tokens this\r\n    * CUSTOM FUNCTION, NOT IN OPENZEPPELIN TEMPLATE\r\n    */\r\n    function tokensIdsByOwner(address owner) public view returns (uint256[] memory) {\r\n        uint256[] memory tokens = new uint256[](_holderTokens[owner].length());\r\n        for (uint i = 0; i < _holderTokens[owner].length(); i++) {\r\n            tokens[i] = _holderTokens[owner].at(i);\r\n        }\r\n        return tokens;\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721Enumerable-totalSupply}.\r\n     */\r\n    function totalSupply() public view virtual override returns (uint256) {\r\n        // _tokenOwners are indexed by tokenIds, so .length() returns the number of tokenIds\r\n        return _tokenOwners.length();\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721Enumerable-tokenByIndex}.\r\n     */\r\n    function tokenByIndex(uint256 index) public view virtual override returns (uint256) {\r\n        (uint256 tokenId, ) = _tokenOwners.at(index);\r\n        return tokenId;\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-approve}.\r\n     */\r\n    function approve(address to, uint256 tokenId) public virtual override {\r\n        address owner = ERC721.ownerOf(tokenId);\r\n        require(to != owner, \"ERC721: approval to current owner\");\r\n\r\n        require(_msgSender() == owner || ERC721.isApprovedForAll(owner, _msgSender()),\r\n            \"ERC721: approve caller is not owner nor approved for all\"\r\n        );\r\n\r\n        _approve(to, tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-getApproved}.\r\n     */\r\n    function getApproved(uint256 tokenId) public view virtual override returns (address) {\r\n        require(_exists(tokenId), \"ERC721: approved query for nonexistent token\");\r\n\r\n        return _tokenApprovals[tokenId];\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-setApprovalForAll}.\r\n     */\r\n    function setApprovalForAll(address operator, bool approved) public virtual override {\r\n        require(operator != _msgSender(), \"ERC721: approve to caller\");\r\n\r\n        _operatorApprovals[_msgSender()][operator] = approved;\r\n        emit ApprovalForAll(_msgSender(), operator, approved);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-isApprovedForAll}.\r\n     */\r\n    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {\r\n        return _operatorApprovals[owner][operator];\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-transferFrom}.\r\n     */\r\n    function transferFrom(address from, address to, uint256 tokenId) public virtual override {\r\n        //solhint-disable-next-line max-line-length\r\n        require(_isApprovedOrOwner(_msgSender(), tokenId), \"ERC721: transfer caller is not owner nor approved\");\r\n\r\n        _transfer(from, to, tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-safeTransferFrom}.\r\n     */\r\n    function safeTransferFrom(address from, address to, uint256 tokenId) public virtual override {\r\n        safeTransferFrom(from, to, tokenId, \"\");\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC721-safeTransferFrom}.\r\n     */\r\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public virtual override {\r\n        require(_isApprovedOrOwner(_msgSender(), tokenId), \"ERC721: transfer caller is not owner nor approved\");\r\n        _safeTransfer(from, to, tokenId, _data);\r\n    }\r\n\r\n    /**\r\n     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients\r\n     * are aware of the ERC721 protocol to prevent tokens from being forever locked.\r\n     *\r\n     * `_data` is additional data, it has no specified format and it is sent in call to `to`.\r\n     *\r\n     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.\r\n     * implement alternative mechanisms to perform token transfer, such as signature-based.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `from` cannot be the zero address.\r\n     * - `to` cannot be the zero address.\r\n     * - `tokenId` token must exist and be owned by `from`.\r\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function _safeTransfer(address from, address to, uint256 tokenId, bytes memory _data) internal virtual {\r\n        _transfer(from, to, tokenId);\r\n        require(_checkOnERC721Received(from, to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\r\n    }\r\n\r\n    /**\r\n     * @dev Returns whether `tokenId` exists.\r\n     *\r\n     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.\r\n     *\r\n     * Tokens start existing when they are minted (`_mint`),\r\n     * and stop existing when they are burned (`_burn`).\r\n     */\r\n    function _exists(uint256 tokenId) internal view virtual returns (bool) {\r\n        return _tokenOwners.contains(tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev Returns whether `spender` is allowed to manage `tokenId`.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must exist.\r\n     */\r\n    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {\r\n        require(_exists(tokenId), \"ERC721: operator query for nonexistent token\");\r\n        address owner = ERC721.ownerOf(tokenId);\r\n        return (spender == owner || getApproved(tokenId) == spender || ERC721.isApprovedForAll(owner, spender));\r\n    }\r\n\r\n    /**\r\n     * @dev Safely mints `tokenId` and transfers it to `to`.\r\n     *\r\n     * Requirements:\r\n     d*\r\n     * - `tokenId` must not exist.\r\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function _safeMint(address to, uint256 tokenId) internal virtual {\r\n        _safeMint(to, tokenId, \"\");\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is\r\n     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.\r\n     */\r\n    function _safeMint(address to, uint256 tokenId, bytes memory _data) internal virtual {\r\n        _mint(to, tokenId);\r\n        require(_checkOnERC721Received(address(0), to, tokenId, _data), \"ERC721: transfer to non ERC721Receiver implementer\");\r\n    }\r\n\r\n    /**\r\n     * @dev Mints `tokenId` and transfers it to `to`.\r\n     *\r\n     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must not exist.\r\n     * - `to` cannot be the zero address.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function _mint(address to, uint256 tokenId) internal virtual {\r\n        require(to != address(0), \"ERC721: mint to the zero address\");\r\n        // DIFFERENT FROM OPENZEPPELIN STANDARD\r\n        // Calls `ERC721._exists` rather than `_exists`\r\n        require(!ERC721._exists(tokenId), \"ERC721: token already minted\");\r\n\r\n        _beforeTokenTransfer(address(0), to, tokenId);\r\n\r\n        _holderTokens[to].add(tokenId);\r\n\r\n        _tokenOwners.set(tokenId, to);\r\n\r\n        emit Transfer(address(0), to, tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev Destroys `tokenId`.\r\n     * The approval is cleared when the token is burned.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must exist.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function _burn(uint256 tokenId) internal virtual {\r\n        address owner = ERC721.ownerOf(tokenId); // internal owner\r\n\r\n        _beforeTokenTransfer(owner, address(0), tokenId);\r\n\r\n        // Clear approvals\r\n        _approve(address(0), tokenId);\r\n\r\n        // Clear metadata (if any)\r\n        if (bytes(_tokenURIs[tokenId]).length != 0) {\r\n            delete _tokenURIs[tokenId];\r\n        }\r\n\r\n        _holderTokens[owner].remove(tokenId);\r\n\r\n        _tokenOwners.remove(tokenId);\r\n\r\n        emit Transfer(owner, address(0), tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev Transfers `tokenId` from `from` to `to`.\r\n     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `to` cannot be the zero address.\r\n     * - `tokenId` token must be owned by `from`.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function _transfer(address from, address to, uint256 tokenId) internal virtual {\r\n        require(ERC721.ownerOf(tokenId) == from, \"ERC721: transfer of token that is not own\"); // internal owner\r\n        require(to != address(0), \"ERC721: transfer to the zero address\");\r\n\r\n        _beforeTokenTransfer(from, to, tokenId);\r\n\r\n        // Clear approvals from the previous owner\r\n        _approve(address(0), tokenId);\r\n\r\n        _holderTokens[from].remove(tokenId);\r\n        _holderTokens[to].add(tokenId);\r\n\r\n        _tokenOwners.set(tokenId, to);\r\n\r\n        emit Transfer(from, to, tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev Sets `_tokenURI` as the tokenURI of `tokenId`.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must exist.\r\n     */\r\n    function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {\r\n        require(_exists(tokenId), \"ERC721Metadata: URI set of nonexistent token\");\r\n        _tokenURIs[tokenId] = _tokenURI;\r\n    }\r\n\r\n    /**\r\n     * @dev Internal function to set the base URI for all token IDs. It is\r\n     * automatically added as a prefix to the value returned in {tokenURI},\r\n     * or to the token ID if {tokenURI} is empty.\r\n     */\r\n    function _setBaseURI(string memory baseURI_) internal virtual {\r\n        _baseURI = baseURI_;\r\n    }\r\n\r\n    /**\r\n     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.\r\n     * The call is not executed if the target address is not a contract.\r\n     *\r\n     * @param from address representing the previous owner of the given token ID\r\n     * @param to target address that will receive the tokens\r\n     * @param tokenId uint256 ID of the token to be transferred\r\n     * @param _data bytes optional data to send along with the call\r\n     * @return bool whether the call correctly returned the expected magic value\r\n     */\r\n    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)\r\n        private returns (bool)\r\n    {\r\n        if (!to.isContract()) {\r\n            return true;\r\n        }\r\n        bytes memory returndata = to.functionCall(abi.encodeWithSelector(\r\n            IERC721Receiver(to).onERC721Received.selector,\r\n            _msgSender(),\r\n            from,\r\n            tokenId,\r\n            _data\r\n        ), \"ERC721: transfer to non ERC721Receiver implementer\");\r\n        bytes4 retval = abi.decode(returndata, (bytes4));\r\n        return (retval == _ERC721_RECEIVED);\r\n    }\r\n\r\n    /**\r\n     * @dev Approve `to` to operate on `tokenId`\r\n     *\r\n     * Emits an {Approval} event.\r\n     */\r\n    function _approve(address to, uint256 tokenId) internal virtual {\r\n        _tokenApprovals[tokenId] = to;\r\n        // DIFFERENT FROM OPENZEPPELIN STANDARD\r\n        // Calls `ownerOf` rather than `ERC721.ownerOf`\r\n        emit Approval(ownerOf(tokenId), to, tokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev Hook that is called before any token transfer. This includes minting\r\n     * and burning.\r\n     *\r\n     * Calling conditions:\r\n     *\r\n     * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be\r\n     * transferred to `to`.\r\n     * - When `from` is zero, `tokenId` will be minted for `to`.\r\n     * - When `to` is zero, ``from``'s `tokenId` will be burned.\r\n     * - `from` cannot be the zero address.\r\n     * - `to` cannot be the zero address.\r\n     *\r\n     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\r\n     */\r\n    function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual { }\r\n}\r\n"
    },
    "MoonCatOrderLookup.sol": {
      "content": "// SPDX-License-Identifier: GPL-3.0-only\r\npragma solidity ^0.7.3;\r\n\r\nimport \"@openzeppelin/contracts/access/Ownable.sol\";\r\nimport \"./IMoonCatRescue.sol\";\r\nimport \"./IMoonCatsWrapped.sol\";\r\n\r\n/**\r\n * @title MoonCat Order Lookup\r\n * @notice A space to have an on-chain record mapping token IDs for OLD_MCRW to their original \"rescue order\" IDs\r\n * @dev This contract exists because there is no MoonCat ID => Rescue ID function\r\n * on the original MoonCatRescue contract. The only way to tell a given MoonCat's\r\n * rescue order if you don't know it is to iterate through the whole `rescueOrder`\r\n * array. Looping through that whole array in a smart contract would be\r\n * prohibitively high gas-usage, and so this alternative is needed.\r\n */\r\ncontract MoonCatOrderLookup is Ownable {\r\n\r\n    MoonCatRescue MCR = MoonCatRescue(0x60cd862c9C687A9dE49aecdC3A99b74A4fc54aB6);\r\n    MoonCatsWrapped OLD_MCRW = MoonCatsWrapped(0x7C40c393DC0f283F318791d746d894DdD3693572);\r\n\r\n    uint256[25600] private _oldTokenIdToRescueOrder;\r\n    uint8 constant VALUE_OFFSET = 10;\r\n\r\n    constructor() Ownable() {}\r\n\r\n    /**\r\n      * @dev Submit a batch of token IDs, and their associated rescue orders\r\n      * This is the primary method for the utility of the contract. Anyone\r\n      * can submit this pairing information (not just the owners of the token)\r\n      * and the information can be submitted in batches.\r\n      *\r\n      * Submitting pairs of token IDs with their rescue orders is verified with\r\n      * the original MoonCatRescue contract before recording.\r\n      *\r\n      * Within the private array holding this information, a VALUE_OFFSET is used\r\n      * to differentiate between \"not set\" and \"set to zero\" (because Solidity\r\n      * has no concept of \"null\" or \"undefined\"). Because the maximum value of the\r\n      * rescue ordering can only be 25,600, we can safely shift the stored values\r\n      * up, and not hit the uint256 limit.\r\n      */\r\n    function submitRescueOrder(\r\n        uint256[] memory oldTokenIds,\r\n        uint16[] memory rescueOrders\r\n    ) public {\r\n        for (uint256 i = 0; i < oldTokenIds.length; i++) {\r\n            require(\r\n                MCR.rescueOrder(rescueOrders[i]) == OLD_MCRW._tokenIDToCatID(oldTokenIds[i]),\r\n                \"Pair does not match!\"\r\n            );\r\n            _oldTokenIdToRescueOrder[oldTokenIds[i]] = rescueOrders[i] + VALUE_OFFSET;\r\n        }\r\n    }\r\n\r\n    /**\r\n      * @dev verify a given old token ID is mapped yet or not\r\n      *\r\n      * This function can use just a zero-check because internally all values are\r\n      * stored with a VALUE_OFFSET added onto them (e.g. storing an actual zero\r\n      * is saved as 0 + VALUE_OFFSET = 10, internally), so anything set to an\r\n      * actual zero means \"unset\".\r\n      */\r\n    function _exists(uint256 oldTokenId) internal view returns (bool) {\r\n        return _oldTokenIdToRescueOrder[oldTokenId] != 0;\r\n    }\r\n\r\n    /**\r\n     * @dev public function to verify whether a given old token ID is mapped or not\r\n     */\r\n    function oldTokenIdExists(uint256 oldTokenId) public view returns(bool) {\r\n        return _exists(oldTokenId);\r\n    }\r\n\r\n    /**\r\n     * @dev given an old token ID, return the rescue order of that MoonCat\r\n     *\r\n     * Throws an error if that particular token ID does not have a recorded\r\n     * mapping to a rescue order.\r\n     */\r\n    function oldTokenIdToRescueOrder(uint256 oldTokenId) public view returns(uint256) {\r\n        require(_exists(oldTokenId), \"That token ID is not mapped yet\");\r\n        return _oldTokenIdToRescueOrder[oldTokenId] - VALUE_OFFSET;\r\n    }\r\n\r\n    /**\r\n     * @dev remove a mapping from the data structure\r\n     *\r\n     * This allows reclaiming some gas, so as part of the re-wrapping process,\r\n     * this gets called by the Acclimator contract, to recoup some gas for the\r\n     * MoonCat owner.\r\n     */\r\n    function removeEntry(uint256 _oldTokenId) public onlyOwner {\r\n        delete _oldTokenIdToRescueOrder[_oldTokenId];\r\n    }\r\n\r\n    /**\r\n     * @dev for a given address, iterate through all the tokens they own in the\r\n     * old wrapping contract, and for each of them, determine how many are mapped\r\n     * in this lookup contract.\r\n     *\r\n     * This method is used by the Acclimator `balanceOf` and `tokenOfOwnerByIndex`\r\n     * to be able to enumerate old-wrapped MoonCats as if they were already\r\n     * re-wrapped in the Acclimator contract.\r\n     */\r\n    function entriesPerAddress(address _owner) public view returns (uint256) {\r\n        uint256 countMapped = 0;\r\n        for (uint256 i = 0; i < OLD_MCRW.balanceOf(_owner); i++) {\r\n            uint256 oldTokenId = OLD_MCRW.tokenOfOwnerByIndex(_owner, i);\r\n            if (_exists(oldTokenId)) {\r\n                countMapped++;\r\n            }\r\n        }\r\n        return countMapped;\r\n    }\r\n}\r\n"
    },
    "IERC998.sol": {
      "content": "pragma solidity ^0.7.3;\r\n\r\n/**\r\n * @title ERC998ERC721 Top-Down Composable Non-Fungible Token\r\n * @dev See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-998.md\r\n * Note: the ERC-165 identifier for this interface is 0x1efdf36a\r\n */\r\ninterface IERC998ERC721TopDown {\r\n    /**\r\n     * @dev This emits when a token receives a child token.\r\n     * @param _from The prior owner of the token.\r\n     * @param _toTokenId The token that receives the child token.\r\n     */\r\n    event ReceivedChild(\r\n        address indexed _from,\r\n        uint256 indexed _toTokenId,\r\n        address indexed _childContract,\r\n        uint256 _childTokenId\r\n    );\r\n\r\n    /**\r\n     * @dev This emits when a child token is transferred from a token to an address.\r\n     * @param _fromTokenId The parent token that the child token is being transferred from.\r\n     * @param _to The new owner address of the child token.\r\n     */\r\n    event TransferChild(\r\n        uint256 indexed _fromTokenId,\r\n        address indexed _to,\r\n        address indexed _childContract,\r\n        uint256 _childTokenId\r\n    );\r\n\r\n    /**\r\n     * @notice Get the root owner of tokenId.\r\n     * @param _tokenId The token to query for a root owner address\r\n     * @return rootOwner The root owner at the top of tree of tokens and ERC998 magic value.\r\n     */\r\n    function rootOwnerOf(uint256 _tokenId)\r\n        external\r\n        view\r\n        returns (bytes32 rootOwner);\r\n\r\n    /**\r\n     * @notice Get the root owner of a child token.\r\n     * @param _childContract The contract address of the child token.\r\n     * @param _childTokenId The tokenId of the child.\r\n     * @return rootOwner The root owner at the top of tree of tokens and ERC998 magic value.\r\n     */\r\n    function rootOwnerOfChild(address _childContract, uint256 _childTokenId)\r\n        external\r\n        view\r\n        returns (bytes32 rootOwner);\r\n\r\n    /**\r\n     * @notice Get the parent tokenId of a child token.\r\n     * @param _childContract The contract address of the child token.\r\n     * @param _childTokenId The tokenId of the child.\r\n     * @return parentTokenOwner The parent address of the parent token and ERC998 magic value\r\n     * @return parentTokenId The parent tokenId of _tokenId\r\n     */\r\n    function ownerOfChild(address _childContract, uint256 _childTokenId)\r\n        external\r\n        view\r\n        returns (bytes32 parentTokenOwner, uint256 parentTokenId);\r\n\r\n    /**\r\n     * @notice A token receives a child token\r\n     * @param _operator The address that caused the transfer.\r\n     * @param _from The owner of the child token.\r\n     * @param _childTokenId The token that is being transferred to the parent.\r\n     * @param _data Up to the first 32 bytes contains an integer which is the receiving parent tokenId.\r\n     */\r\n    function onERC721Received(\r\n        address _operator,\r\n        address _from,\r\n        uint256 _childTokenId,\r\n        bytes calldata _data\r\n    ) external returns (bytes4);\r\n\r\n    /**\r\n     * @notice Transfer child token from top-down composable to address.\r\n     * @param _fromTokenId The owning token to transfer from.\r\n     * @param _to The address that receives the child token\r\n     * @param _childContract The ERC721 contract of the child token.\r\n     * @param _childTokenId The tokenId of the token that is being transferred.\r\n     */\r\n    function transferChild(\r\n        uint256 _fromTokenId,\r\n        address _to,\r\n        address _childContract,\r\n        uint256 _childTokenId\r\n    ) external;\r\n\r\n    /**\r\n     * @notice Transfer child token from top-down composable to address.\r\n     * @param _fromTokenId The owning token to transfer from.\r\n     * @param _to The address that receives the child token\r\n     * @param _childContract The ERC721 contract of the child token.\r\n     * @param _childTokenId The tokenId of the token that is being transferred.\r\n     */\r\n    function safeTransferChild(\r\n        uint256 _fromTokenId,\r\n        address _to,\r\n        address _childContract,\r\n        uint256 _childTokenId\r\n    ) external;\r\n\r\n    /**\r\n     * @notice Transfer child token from top-down composable to address.\r\n     * @param _fromTokenId The owning token to transfer from.\r\n     * @param _to The address that receives the child token\r\n     * @param _childContract The ERC721 contract of the child token.\r\n     * @param _childTokenId The tokenId of the token that is being transferred.\r\n     * @param _data Additional data with no specified format\r\n     */\r\n    function safeTransferChild(\r\n        uint256 _fromTokenId,\r\n        address _to,\r\n        address _childContract,\r\n        uint256 _childTokenId,\r\n        bytes calldata _data\r\n    ) external;\r\n\r\n    /**\r\n     * @notice Transfer bottom-up composable child token from top-down composable to other ERC721 token.\r\n     * @param _fromTokenId The owning token to transfer from.\r\n     * @param _toContract The ERC721 contract of the receiving token\r\n     * @param _toTokenId The receiving token\r\n     * @param _childContract The bottom-up composable contract of the child token.\r\n     * @param _childTokenId The token that is being transferred.\r\n     * @param _data Additional data with no specified format\r\n     */\r\n    function transferChildToParent(\r\n        uint256 _fromTokenId,\r\n        address _toContract,\r\n        uint256 _toTokenId,\r\n        address _childContract,\r\n        uint256 _childTokenId,\r\n        bytes calldata _data\r\n    ) external;\r\n\r\n    /**\r\n     * @notice Get a child token from an ERC721 contract.\r\n     * @param _from The address that owns the child token.\r\n     * @param _tokenId The token that becomes the parent owner\r\n     * @param _childContract The ERC721 contract of the child token\r\n     * @param _childTokenId The tokenId of the child token\r\n     */\r\n    function getChild(\r\n        address _from,\r\n        uint256 _tokenId,\r\n        address _childContract,\r\n        uint256 _childTokenId\r\n    ) external;\r\n}\r\n\r\n/**\r\n * @dev The ERC-165 identifier for this interface is 0xa344afe4\r\n */\r\ninterface IERC998ERC721TopDownEnumerable {\r\n    /**\r\n     * @notice Get the total number of child contracts with tokens that are owned by tokenId.\r\n     * @param _tokenId The parent token of child tokens in child contracts\r\n     * @return uint256 The total number of child contracts with tokens owned by tokenId.\r\n     */\r\n    function totalChildContracts(uint256 _tokenId)\r\n        external\r\n        view\r\n        returns (uint256);\r\n\r\n    /**\r\n     * @notice Get child contract by tokenId and index\r\n     * @param _tokenId The parent token of child tokens in child contract\r\n     * @param _index The index position of the child contract\r\n     * @return childContract The contract found at the tokenId and index.\r\n     */\r\n    function childContractByIndex(uint256 _tokenId, uint256 _index)\r\n        external\r\n        view\r\n        returns (address childContract);\r\n\r\n    /**\r\n     * @notice Get the total number of child tokens owned by tokenId that exist in a child contract.\r\n     * @param _tokenId The parent token of child tokens\r\n     * @param _childContract The child contract containing the child tokens\r\n     * @return uint256 The total number of child tokens found in child contract that are owned by tokenId.\r\n     */\r\n    function totalChildTokens(uint256 _tokenId, address _childContract)\r\n        external\r\n        view\r\n        returns (uint256);\r\n\r\n    /**\r\n     * @notice Get child token owned by tokenId, in child contract, at index position\r\n     * @param _tokenId The parent token of the child token\r\n     * @param _childContract The child contract of the child token\r\n     * @param _index The index position of the child token.\r\n     * @return childTokenId The child tokenId for the parent token, child token and index\r\n     */\r\n    function childTokenByIndex(\r\n        uint256 _tokenId,\r\n        address _childContract,\r\n        uint256 _index\r\n    ) external view returns (uint256 childTokenId);\r\n}\r\n\r\ninterface IERC998ERC721BottomUp {\r\n    /**\r\n     * @notice Transfer token from owner address to a token\r\n     * @param _from The owner address\r\n     * @param _toContract The ERC721 contract of the receiving token\r\n     * @param _toTokenId The receiving token\r\n     * @param _data Additional data with no specified format\r\n     */\r\n    function transferToParent(\r\n        address _from,\r\n        address _toContract,\r\n        uint256 _toTokenId,\r\n        uint256 _tokenId,\r\n        bytes calldata _data\r\n    ) external;\r\n}"
    },
    "IMoonCatRescue.sol": {
      "content": "pragma solidity ^0.7.3;\r\ninterface MoonCatRescue {\r\n    function getCatDetails(bytes5 catId)\r\n        external\r\n        view\r\n        returns (\r\n            bytes5 id,\r\n            address owner,\r\n            bytes32 name,\r\n            address onlyOfferTo,\r\n            uint256 offerPrice,\r\n            address requester,\r\n            uint256 requestPrice\r\n        );\r\n\r\n    function rescueOrder(uint256 _rescueOrder)\r\n        external\r\n        view\r\n        returns (bytes5 catId);\r\n\r\n    function acceptAdoptionOffer(bytes5 catId) external payable;\r\n\r\n    function acceptAdoptionRequest(bytes5 catId) external;\r\n\r\n    function adoptionRequests(bytes5 _catId)\r\n        external\r\n        view\r\n        returns (\r\n            bool exists,\r\n            bytes5 catId,\r\n            address requester,\r\n            uint256 price\r\n        );\r\n\r\n    function adoptionOffers(bytes5 _catId)\r\n        external\r\n        view\r\n        returns (\r\n            bool exists,\r\n            bytes5 catId,\r\n            address seller,\r\n            uint256 price,\r\n            address offerOnlyTo\r\n        );\r\n\r\n    function giveCat(bytes5 catId, address to) external;\r\n\r\n    function catOwners(bytes5) external view returns (address);\r\n\r\n    function makeAdoptionOfferToAddress(bytes5 catId, uint256 price, address to) external;\r\n\r\n    function makeAdoptionOffer(bytes5 catId, uint256 price) external;\r\n\r\n    function withdraw() external;\r\n}\r\n"
    },
    "IMoonCatsWrapped.sol": {
      "content": "pragma solidity ^0.7.3;\r\ninterface MoonCatsWrapped {\r\n\r\n    /**\r\n     * @dev in the original contract, this is a public map property, so is\r\n     * using the default getter action, which does NOT check for \"exists\";\r\n     * if this returns a zero, it might be referencing token ID #0, or it might\r\n     * be meaning \"that MoonCat ID is not wrapped in this contract\".\r\n     */\r\n    function _catIDToTokenID(bytes5 catId) external pure\r\n        returns (uint256);\r\n\r\n    /**\r\n     * @dev in the original contract, this is a public map property, so is\r\n     * using the default getter action, which does NOT check for \"exists\".\r\n     * However, no MoonCat has an ID of `0x0000000000`, so if this returns\r\n     * all zeroes, it means \"that token ID does not exist in this contract\".\r\n     */\r\n    function _tokenIDToCatID(uint256 _tokenID) external pure\r\n        returns (bytes5 catId);\r\n\r\n    function safeTransferFrom(address from, address to, uint256 tokenId) external;\r\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) external;\r\n    function balanceOf(address owner) external view returns (uint256 balance);\r\n    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);\r\n    function wrap(bytes5 catId) external;\r\n    function unwrap(uint256 tokenID) external;\r\n    function ownerOf(uint256 tokenID) external view returns(address);\r\n    function setApprovalForAll(address operator, bool _approved) external;\r\n    function isApprovedForAll(address owner, address operator) external view returns (bool);\r\n    function approve(address to, uint256 tokenId) external;\r\n}"
    },
    "@openzeppelin/contracts/utils/Context.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\n/*\r\n * @dev Provides information about the current execution context, including the\r\n * sender of the transaction and its data. While these are generally available\r\n * via msg.sender and msg.data, they should not be accessed in such a direct\r\n * manner, since when dealing with GSN meta-transactions the account sending and\r\n * paying for execution may not be the actual sender (as far as an application\r\n * is concerned).\r\n *\r\n * This contract is only required for intermediate, library-like contracts.\r\n */\r\nabstract contract Context {\r\n    function _msgSender() internal view virtual returns (address payable) {\r\n        return msg.sender;\r\n    }\r\n\r\n    function _msgData() internal view virtual returns (bytes memory) {\r\n        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\r\n        return msg.data;\r\n    }\r\n}\r\n"
    },
    "@openzeppelin/contracts/access/Ownable.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\nimport \"../utils/Context.sol\";\r\n/**\r\n * @dev Contract module which provides a basic access control mechanism, where\r\n * there is an account (an owner) that can be granted exclusive access to\r\n * specific functions.\r\n *\r\n * By default, the owner account will be the one that deploys the contract. This\r\n * can later be changed with {transferOwnership}.\r\n *\r\n * This module is used through inheritance. It will make available the modifier\r\n * `onlyOwner`, which can be applied to your functions to restrict their use to\r\n * the owner.\r\n */\r\nabstract contract Ownable is Context {\r\n    address private _owner;\r\n\r\n    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\r\n\r\n    /**\r\n     * @dev Initializes the contract setting the deployer as the initial owner.\r\n     */\r\n    constructor () internal {\r\n        address msgSender = _msgSender();\r\n        _owner = msgSender;\r\n        emit OwnershipTransferred(address(0), msgSender);\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the address of the current owner.\r\n     */\r\n    function owner() public view virtual returns (address) {\r\n        return _owner;\r\n    }\r\n\r\n    /**\r\n     * @dev Throws if called by any account other than the owner.\r\n     */\r\n    modifier onlyOwner() {\r\n        require(owner() == _msgSender(), \"Ownable: caller is not the owner\");\r\n        _;\r\n    }\r\n\r\n    /**\r\n     * @dev Leaves the contract without owner. It will not be possible to call\r\n     * `onlyOwner` functions anymore. Can only be called by the current owner.\r\n     *\r\n     * NOTE: Renouncing ownership will leave the contract without an owner,\r\n     * thereby removing any functionality that is only available to the owner.\r\n     */\r\n    function renounceOwnership() public virtual onlyOwner {\r\n        emit OwnershipTransferred(_owner, address(0));\r\n        _owner = address(0);\r\n    }\r\n\r\n    /**\r\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\r\n     * Can only be called by the current owner.\r\n     */\r\n    function transferOwnership(address newOwner) public virtual onlyOwner {\r\n        require(newOwner != address(0), \"Ownable: new owner is the zero address\");\r\n        emit OwnershipTransferred(_owner, newOwner);\r\n        _owner = newOwner;\r\n    }\r\n}\r\n"
    },
    "@openzeppelin/contracts/utils/Pausable.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\nimport \"./Context.sol\";\r\n\r\n/**\r\n * @dev Contract module which allows children to implement an emergency stop\r\n * mechanism that can be triggered by an authorized account.\r\n *\r\n * This module is used through inheritance. It will make available the\r\n * modifiers `whenNotPaused` and `whenPaused`, which can be applied to\r\n * the functions of your contract. Note that they will not be pausable by\r\n * simply including this module, only once the modifiers are put in place.\r\n */\r\nabstract contract Pausable is Context {\r\n    /**\r\n     * @dev Emitted when the pause is triggered by `account`.\r\n     */\r\n    event Paused(address account);\r\n\r\n    /**\r\n     * @dev Emitted when the pause is lifted by `account`.\r\n     */\r\n    event Unpaused(address account);\r\n\r\n    bool private _paused;\r\n\r\n    /**\r\n     * @dev Initializes the contract in unpaused state.\r\n     */\r\n    constructor () internal {\r\n        _paused = false;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the contract is paused, and false otherwise.\r\n     */\r\n    function paused() public view virtual returns (bool) {\r\n        return _paused;\r\n    }\r\n\r\n    /**\r\n     * @dev Modifier to make a function callable only when the contract is not paused.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The contract must not be paused.\r\n     */\r\n    modifier whenNotPaused() {\r\n        require(!paused(), \"Pausable: paused\");\r\n        _;\r\n    }\r\n\r\n    /**\r\n     * @dev Modifier to make a function callable only when the contract is paused.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The contract must be paused.\r\n     */\r\n    modifier whenPaused() {\r\n        require(paused(), \"Pausable: not paused\");\r\n        _;\r\n    }\r\n\r\n    /**\r\n     * @dev Triggers stopped state.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The contract must not be paused.\r\n     */\r\n    function _pause() internal virtual whenNotPaused {\r\n        _paused = true;\r\n        emit Paused(_msgSender());\r\n    }\r\n\r\n    /**\r\n     * @dev Returns to normal state.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The contract must be paused.\r\n     */\r\n    function _unpause() internal virtual whenPaused {\r\n        _paused = false;\r\n        emit Unpaused(_msgSender());\r\n    }\r\n}\r\n"
    },
    "@openzeppelin/contracts/token/ERC721/IERC721.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.2 <0.8.0;\r\n\r\nimport \"../../introspection/IERC165.sol\";\r\n\r\n/**\r\n * @dev Required interface of an ERC721 compliant contract.\r\n */\r\ninterface IERC721 is IERC165 {\r\n    /**\r\n     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.\r\n     */\r\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\r\n\r\n    /**\r\n     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.\r\n     */\r\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\r\n\r\n    /**\r\n     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.\r\n     */\r\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\r\n\r\n    /**\r\n     * @dev Returns the number of tokens in ``owner``'s account.\r\n     */\r\n    function balanceOf(address owner) external view returns (uint256 balance);\r\n\r\n    /**\r\n     * @dev Returns the owner of the `tokenId` token.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must exist.\r\n     */\r\n    function ownerOf(uint256 tokenId) external view returns (address owner);\r\n\r\n    /**\r\n     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients\r\n     * are aware of the ERC721 protocol to prevent tokens from being forever locked.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `from` cannot be the zero address.\r\n     * - `to` cannot be the zero address.\r\n     * - `tokenId` token must exist and be owned by `from`.\r\n     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.\r\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function safeTransferFrom(address from, address to, uint256 tokenId) external;\r\n\r\n    /**\r\n     * @dev Transfers `tokenId` token from `from` to `to`.\r\n     *\r\n     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `from` cannot be the zero address.\r\n     * - `to` cannot be the zero address.\r\n     * - `tokenId` token must be owned by `from`.\r\n     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function transferFrom(address from, address to, uint256 tokenId) external;\r\n\r\n    /**\r\n     * @dev Gives permission to `to` to transfer `tokenId` token to another account.\r\n     * The approval is cleared when the token is transferred.\r\n     *\r\n     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The caller must own the token or be an approved operator.\r\n     * - `tokenId` must exist.\r\n     *\r\n     * Emits an {Approval} event.\r\n     */\r\n    function approve(address to, uint256 tokenId) external;\r\n\r\n    /**\r\n     * @dev Returns the account approved for `tokenId` token.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `tokenId` must exist.\r\n     */\r\n    function getApproved(uint256 tokenId) external view returns (address operator);\r\n\r\n    /**\r\n     * @dev Approve or remove `operator` as an operator for the caller.\r\n     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The `operator` cannot be the caller.\r\n     *\r\n     * Emits an {ApprovalForAll} event.\r\n     */\r\n    function setApprovalForAll(address operator, bool _approved) external;\r\n\r\n    /**\r\n     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.\r\n     *\r\n     * See {setApprovalForAll}\r\n     */\r\n    function isApprovedForAll(address owner, address operator) external view returns (bool);\r\n\r\n    /**\r\n      * @dev Safely transfers `tokenId` token from `from` to `to`.\r\n      *\r\n      * Requirements:\r\n      *\r\n      * - `from` cannot be the zero address.\r\n      * - `to` cannot be the zero address.\r\n      * - `tokenId` token must exist and be owned by `from`.\r\n      * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\r\n      * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\r\n      *\r\n      * Emits a {Transfer} event.\r\n      */\r\n    function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;\r\n}\r\n"
    },
    "@openzeppelin/contracts/token/ERC721/IERC721Metadata.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.2 <0.8.0;\r\n\r\nimport \"./IERC721.sol\";\r\n\r\n/**\r\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\r\n * @dev See https://eips.ethereum.org/EIPS/eip-721\r\n */\r\ninterface IERC721Metadata is IERC721 {\r\n\r\n    /**\r\n     * @dev Returns the token collection name.\r\n     */\r\n    function name() external view returns (string memory);\r\n\r\n    /**\r\n     * @dev Returns the token collection symbol.\r\n     */\r\n    function symbol() external view returns (string memory);\r\n\r\n    /**\r\n     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.\r\n     */\r\n    function tokenURI(uint256 tokenId) external view returns (string memory);\r\n}\r\n"
    },
    "@openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.2 <0.8.0;\r\n\r\nimport \"./IERC721.sol\";\r\n\r\n/**\r\n * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension\r\n * @dev See https://eips.ethereum.org/EIPS/eip-721\r\n */\r\ninterface IERC721Enumerable is IERC721 {\r\n\r\n    /**\r\n     * @dev Returns the total amount of tokens stored by the contract.\r\n     */\r\n    function totalSupply() external view returns (uint256);\r\n\r\n    /**\r\n     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.\r\n     * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.\r\n     */\r\n    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);\r\n\r\n    /**\r\n     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.\r\n     * Use along with {totalSupply} to enumerate all tokens.\r\n     */\r\n    function tokenByIndex(uint256 index) external view returns (uint256);\r\n}\r\n"
    },
    "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\n/**\r\n * @title ERC721 token receiver interface\r\n * @dev Interface for any contract that wants to support safeTransfers\r\n * from ERC721 asset contracts.\r\n */\r\ninterface IERC721Receiver {\r\n    /**\r\n     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}\r\n     * by `operator` from `from`, this function is called.\r\n     *\r\n     * It must return its Solidity selector to confirm the token transfer.\r\n     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.\r\n     *\r\n     * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.\r\n     */\r\n    function onERC721Received(address operator, address from, uint256 tokenId, bytes calldata data) external returns (bytes4);\r\n}\r\n"
    },
    "@openzeppelin/contracts/token/ERC721/ERC721Holder.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\nimport \"./IERC721Receiver.sol\";\r\n\r\n  /**\r\n   * @dev Implementation of the {IERC721Receiver} interface.\r\n   *\r\n   * Accepts all token transfers. \r\n   * Make sure the contract is able to use its token with {IERC721-safeTransferFrom}, {IERC721-approve} or {IERC721-setApprovalForAll}.\r\n   */\r\ncontract ERC721Holder is IERC721Receiver {\r\n\r\n    /**\r\n     * @dev See {IERC721Receiver-onERC721Received}.\r\n     *\r\n     * Always returns `IERC721Receiver.onERC721Received.selector`.\r\n     */\r\n    function onERC721Received(address, address, uint256, bytes memory) public virtual override returns (bytes4) {\r\n        return this.onERC721Received.selector;\r\n    }\r\n}\r\n"
    },
    "@openzeppelin/contracts/introspection/ERC165.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\nimport \"./IERC165.sol\";\r\n\r\n/**\r\n * @dev Implementation of the {IERC165} interface.\r\n *\r\n * Contracts may inherit from this and call {_registerInterface} to declare\r\n * their support of an interface.\r\n */\r\nabstract contract ERC165 is IERC165 {\r\n    /*\r\n     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7\r\n     */\r\n    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;\r\n\r\n    /**\r\n     * @dev Mapping of interface ids to whether or not it's supported.\r\n     */\r\n    mapping(bytes4 => bool) private _supportedInterfaces;\r\n\r\n    constructor () internal {\r\n        // Derived contracts need only register support for their own interfaces,\r\n        // we register support for ERC165 itself here\r\n        _registerInterface(_INTERFACE_ID_ERC165);\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC165-supportsInterface}.\r\n     *\r\n     * Time complexity O(1), guaranteed to always use less than 30 000 gas.\r\n     */\r\n    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\r\n        return _supportedInterfaces[interfaceId];\r\n    }\r\n\r\n    /**\r\n     * @dev Registers the contract as an implementer of the interface defined by\r\n     * `interfaceId`. Support of the actual ERC165 interface is automatic and\r\n     * registering its interface id is not required.\r\n     *\r\n     * See {IERC165-supportsInterface}.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).\r\n     */\r\n    function _registerInterface(bytes4 interfaceId) internal virtual {\r\n        require(interfaceId != 0xffffffff, \"ERC165: invalid interface id\");\r\n        _supportedInterfaces[interfaceId] = true;\r\n    }\r\n}\r\n"
    },
    "@openzeppelin/contracts/introspection/IERC165.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\n/**\r\n * @dev Interface of the ERC165 standard, as defined in the\r\n * https://eips.ethereum.org/EIPS/eip-165[EIP].\r\n *\r\n * Implementers can declare support of contract interfaces, which can then be\r\n * queried by others ({ERC165Checker}).\r\n *\r\n * For an implementation, see {ERC165}.\r\n */\r\ninterface IERC165 {\r\n    /**\r\n     * @dev Returns true if this contract implements the interface defined by\r\n     * `interfaceId`. See the corresponding\r\n     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]\r\n     * to learn more about how these ids are created.\r\n     *\r\n     * This function call must use less than 30 000 gas.\r\n     */\r\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\r\n}\r\n"
    },
    "@openzeppelin/contracts/math/SafeMath.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\n/**\r\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\r\n * checks.\r\n *\r\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\r\n * in bugs, because programmers usually assume that an overflow raises an\r\n * error, which is the standard behavior in high level programming languages.\r\n * `SafeMath` restores this intuition by reverting the transaction when an\r\n * operation overflows.\r\n *\r\n * Using this library instead of the unchecked operations eliminates an entire\r\n * class of bugs, so it's recommended to use it always.\r\n */\r\nlibrary SafeMath {\r\n    /**\r\n     * @dev Returns the addition of two unsigned integers, with an overflow flag.\r\n     *\r\n     * _Available since v3.4._\r\n     */\r\n    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {\r\n        uint256 c = a + b;\r\n        if (c < a) return (false, 0);\r\n        return (true, c);\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the substraction of two unsigned integers, with an overflow flag.\r\n     *\r\n     * _Available since v3.4._\r\n     */\r\n    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {\r\n        if (b > a) return (false, 0);\r\n        return (true, a - b);\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.\r\n     *\r\n     * _Available since v3.4._\r\n     */\r\n    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {\r\n        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\r\n        // benefit is lost if 'b' is also tested.\r\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\r\n        if (a == 0) return (true, 0);\r\n        uint256 c = a * b;\r\n        if (c / a != b) return (false, 0);\r\n        return (true, c);\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the division of two unsigned integers, with a division by zero flag.\r\n     *\r\n     * _Available since v3.4._\r\n     */\r\n    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {\r\n        if (b == 0) return (false, 0);\r\n        return (true, a / b);\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.\r\n     *\r\n     * _Available since v3.4._\r\n     */\r\n    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {\r\n        if (b == 0) return (false, 0);\r\n        return (true, a % b);\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the addition of two unsigned integers, reverting on\r\n     * overflow.\r\n     *\r\n     * Counterpart to Solidity's `+` operator.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - Addition cannot overflow.\r\n     */\r\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        uint256 c = a + b;\r\n        require(c >= a, \"SafeMath: addition overflow\");\r\n        return c;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the subtraction of two unsigned integers, reverting on\r\n     * overflow (when the result is negative).\r\n     *\r\n     * Counterpart to Solidity's `-` operator.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - Subtraction cannot overflow.\r\n     */\r\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        require(b <= a, \"SafeMath: subtraction overflow\");\r\n        return a - b;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the multiplication of two unsigned integers, reverting on\r\n     * overflow.\r\n     *\r\n     * Counterpart to Solidity's `*` operator.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - Multiplication cannot overflow.\r\n     */\r\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        if (a == 0) return 0;\r\n        uint256 c = a * b;\r\n        require(c / a == b, \"SafeMath: multiplication overflow\");\r\n        return c;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the integer division of two unsigned integers, reverting on\r\n     * division by zero. The result is rounded towards zero.\r\n     *\r\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\r\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\r\n     * uses an invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        require(b > 0, \"SafeMath: division by zero\");\r\n        return a / b;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\r\n     * reverting when dividing by zero.\r\n     *\r\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\r\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\r\n     * invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        require(b > 0, \"SafeMath: modulo by zero\");\r\n        return a % b;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\r\n     * overflow (when the result is negative).\r\n     *\r\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\r\n     * message unnecessarily. For custom revert reasons use {trySub}.\r\n     *\r\n     * Counterpart to Solidity's `-` operator.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - Subtraction cannot overflow.\r\n     */\r\n    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\r\n        require(b <= a, errorMessage);\r\n        return a - b;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the integer division of two unsigned integers, reverting with custom message on\r\n     * division by zero. The result is rounded towards zero.\r\n     *\r\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\r\n     * message unnecessarily. For custom revert reasons use {tryDiv}.\r\n     *\r\n     * Counterpart to Solidity's `/` operator. Note: this function uses a\r\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\r\n     * uses an invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\r\n        require(b > 0, errorMessage);\r\n        return a / b;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\r\n     * reverting with custom message when dividing by zero.\r\n     *\r\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\r\n     * message unnecessarily. For custom revert reasons use {tryMod}.\r\n     *\r\n     * Counterpart to Solidity's `%` operator. This function uses a `revert`\r\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\r\n     * invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\r\n        require(b > 0, errorMessage);\r\n        return a % b;\r\n    }\r\n}\r\n"
    },
    "@openzeppelin/contracts/utils/Address.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.2 <0.8.0;\r\n\r\n/**\r\n * @dev Collection of functions related to the address type\r\n */\r\nlibrary Address {\r\n    /**\r\n     * @dev Returns true if `account` is a contract.\r\n     *\r\n     * [IMPORTANT]\r\n     * ====\r\n     * It is unsafe to assume that an address for which this function returns\r\n     * false is an externally-owned account (EOA) and not a contract.\r\n     *\r\n     * Among others, `isContract` will return false for the following\r\n     * types of addresses:\r\n     *\r\n     *  - an externally-owned account\r\n     *  - a contract in construction\r\n     *  - an address where a contract will be created\r\n     *  - an address where a contract lived, but was destroyed\r\n     * ====\r\n     */\r\n    function isContract(address account) internal view returns (bool) {\r\n        // This method relies on extcodesize, which returns 0 for contracts in\r\n        // construction, since the code is only stored at the end of the\r\n        // constructor execution.\r\n\r\n        uint256 size;\r\n        // solhint-disable-next-line no-inline-assembly\r\n        assembly { size := extcodesize(account) }\r\n        return size > 0;\r\n    }\r\n\r\n    /**\r\n     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to\r\n     * `recipient`, forwarding all available gas and reverting on errors.\r\n     *\r\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\r\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\r\n     * imposed by `transfer`, making them unable to receive funds via\r\n     * `transfer`. {sendValue} removes this limitation.\r\n     *\r\n     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\r\n     *\r\n     * IMPORTANT: because control is transferred to `recipient`, care must be\r\n     * taken to not create reentrancy vulnerabilities. Consider using\r\n     * {ReentrancyGuard} or the\r\n     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\r\n     */\r\n    function sendValue(address payable recipient, uint256 amount) internal {\r\n        require(address(this).balance >= amount, \"Address: insufficient balance\");\r\n\r\n        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value\r\n        (bool success, ) = recipient.call{ value: amount }(\"\");\r\n        require(success, \"Address: unable to send value, recipient may have reverted\");\r\n    }\r\n\r\n    /**\r\n     * @dev Performs a Solidity function call using a low level `call`. A\r\n     * plain`call` is an unsafe replacement for a function call: use this\r\n     * function instead.\r\n     *\r\n     * If `target` reverts with a revert reason, it is bubbled up by this\r\n     * function (like regular Solidity function calls).\r\n     *\r\n     * Returns the raw returned data. To convert to the expected return value,\r\n     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `target` must be a contract.\r\n     * - calling `target` with `data` must not revert.\r\n     *\r\n     * _Available since v3.1._\r\n     */\r\n    function functionCall(address target, bytes memory data) internal returns (bytes memory) {\r\n      return functionCall(target, data, \"Address: low-level call failed\");\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\r\n     * `errorMessage` as a fallback revert reason when `target` reverts.\r\n     *\r\n     * _Available since v3.1._\r\n     */\r\n    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {\r\n        return functionCallWithValue(target, data, 0, errorMessage);\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\r\n     * but also transferring `value` wei to `target`.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - the calling contract must have an ETH balance of at least `value`.\r\n     * - the called Solidity function must be `payable`.\r\n     *\r\n     * _Available since v3.1._\r\n     */\r\n    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {\r\n        return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\r\n     * with `errorMessage` as a fallback revert reason when `target` reverts.\r\n     *\r\n     * _Available since v3.1._\r\n     */\r\n    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {\r\n        require(address(this).balance >= value, \"Address: insufficient balance for call\");\r\n        require(isContract(target), \"Address: call to non-contract\");\r\n\r\n        // solhint-disable-next-line avoid-low-level-calls\r\n        (bool success, bytes memory returndata) = target.call{ value: value }(data);\r\n        return _verifyCallResult(success, returndata, errorMessage);\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\r\n     * but performing a static call.\r\n     *\r\n     * _Available since v3.3._\r\n     */\r\n    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {\r\n        return functionStaticCall(target, data, \"Address: low-level static call failed\");\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\r\n     * but performing a static call.\r\n     *\r\n     * _Available since v3.3._\r\n     */\r\n    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {\r\n        require(isContract(target), \"Address: static call to non-contract\");\r\n\r\n        // solhint-disable-next-line avoid-low-level-calls\r\n        (bool success, bytes memory returndata) = target.staticcall(data);\r\n        return _verifyCallResult(success, returndata, errorMessage);\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\r\n     * but performing a delegate call.\r\n     *\r\n     * _Available since v3.4._\r\n     */\r\n    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {\r\n        return functionDelegateCall(target, data, \"Address: low-level delegate call failed\");\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\r\n     * but performing a delegate call.\r\n     *\r\n     * _Available since v3.4._\r\n     */\r\n    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {\r\n        require(isContract(target), \"Address: delegate call to non-contract\");\r\n\r\n        // solhint-disable-next-line avoid-low-level-calls\r\n        (bool success, bytes memory returndata) = target.delegatecall(data);\r\n        return _verifyCallResult(success, returndata, errorMessage);\r\n    }\r\n\r\n    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {\r\n        if (success) {\r\n            return returndata;\r\n        } else {\r\n            // Look for revert reason and bubble it up if present\r\n            if (returndata.length > 0) {\r\n                // The easiest way to bubble the revert reason is using memory via assembly\r\n\r\n                // solhint-disable-next-line no-inline-assembly\r\n                assembly {\r\n                    let returndata_size := mload(returndata)\r\n                    revert(add(32, returndata), returndata_size)\r\n                }\r\n            } else {\r\n                revert(errorMessage);\r\n            }\r\n        }\r\n    }\r\n}\r\n"
    },
    "@openzeppelin/contracts/utils/EnumerableSet.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\n/**\r\n * @dev Library for managing\r\n * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive\r\n * types.\r\n *\r\n * Sets have the following properties:\r\n *\r\n * - Elements are added, removed, and checked for existence in constant time\r\n * (O(1)).\r\n * - Elements are enumerated in O(n). No guarantees are made on the ordering.\r\n *\r\n * ```\r\n * contract Example {\r\n *     // Add the library methods\r\n *     using EnumerableSet for EnumerableSet.AddressSet;\r\n *\r\n *     // Declare a set state variable\r\n *     EnumerableSet.AddressSet private mySet;\r\n * }\r\n * ```\r\n *\r\n * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)\r\n * and `uint256` (`UintSet`) are supported.\r\n */\r\nlibrary EnumerableSet {\r\n    // To implement this library for multiple types with as little code\r\n    // repetition as possible, we write it in terms of a generic Set type with\r\n    // bytes32 values.\r\n    // The Set implementation uses private functions, and user-facing\r\n    // implementations (such as AddressSet) are just wrappers around the\r\n    // underlying Set.\r\n    // This means that we can only create new EnumerableSets for types that fit\r\n    // in bytes32.\r\n\r\n    struct Set {\r\n        // Storage of set values\r\n        bytes32[] _values;\r\n\r\n        // Position of the value in the `values` array, plus 1 because index 0\r\n        // means a value is not in the set.\r\n        mapping (bytes32 => uint256) _indexes;\r\n    }\r\n\r\n    /**\r\n     * @dev Add a value to a set. O(1).\r\n     *\r\n     * Returns true if the value was added to the set, that is if it was not\r\n     * already present.\r\n     */\r\n    function _add(Set storage set, bytes32 value) private returns (bool) {\r\n        if (!_contains(set, value)) {\r\n            set._values.push(value);\r\n            // The value is stored at length-1, but we add 1 to all indexes\r\n            // and use 0 as a sentinel value\r\n            set._indexes[value] = set._values.length;\r\n            return true;\r\n        } else {\r\n            return false;\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev Removes a value from a set. O(1).\r\n     *\r\n     * Returns true if the value was removed from the set, that is if it was\r\n     * present.\r\n     */\r\n    function _remove(Set storage set, bytes32 value) private returns (bool) {\r\n        // We read and store the value's index to prevent multiple reads from the same storage slot\r\n        uint256 valueIndex = set._indexes[value];\r\n\r\n        if (valueIndex != 0) { // Equivalent to contains(set, value)\r\n            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in\r\n            // the array, and then remove the last element (sometimes called as 'swap and pop').\r\n            // This modifies the order of the array, as noted in {at}.\r\n\r\n            uint256 toDeleteIndex = valueIndex - 1;\r\n            uint256 lastIndex = set._values.length - 1;\r\n\r\n            // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs\r\n            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.\r\n\r\n            bytes32 lastvalue = set._values[lastIndex];\r\n\r\n            // Move the last value to the index where the value to delete is\r\n            set._values[toDeleteIndex] = lastvalue;\r\n            // Update the index for the moved value\r\n            set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based\r\n\r\n            // Delete the slot where the moved value was stored\r\n            set._values.pop();\r\n\r\n            // Delete the index for the deleted slot\r\n            delete set._indexes[value];\r\n\r\n            return true;\r\n        } else {\r\n            return false;\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the value is in the set. O(1).\r\n     */\r\n    function _contains(Set storage set, bytes32 value) private view returns (bool) {\r\n        return set._indexes[value] != 0;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of values on the set. O(1).\r\n     */\r\n    function _length(Set storage set) private view returns (uint256) {\r\n        return set._values.length;\r\n    }\r\n\r\n   /**\r\n    * @dev Returns the value stored at position `index` in the set. O(1).\r\n    *\r\n    * Note that there are no guarantees on the ordering of values inside the\r\n    * array, and it may change when more values are added or removed.\r\n    *\r\n    * Requirements:\r\n    *\r\n    * - `index` must be strictly less than {length}.\r\n    */\r\n    function _at(Set storage set, uint256 index) private view returns (bytes32) {\r\n        require(set._values.length > index, \"EnumerableSet: index out of bounds\");\r\n        return set._values[index];\r\n    }\r\n\r\n    // Bytes32Set\r\n\r\n    struct Bytes32Set {\r\n        Set _inner;\r\n    }\r\n\r\n    /**\r\n     * @dev Add a value to a set. O(1).\r\n     *\r\n     * Returns true if the value was added to the set, that is if it was not\r\n     * already present.\r\n     */\r\n    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {\r\n        return _add(set._inner, value);\r\n    }\r\n\r\n    /**\r\n     * @dev Removes a value from a set. O(1).\r\n     *\r\n     * Returns true if the value was removed from the set, that is if it was\r\n     * present.\r\n     */\r\n    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {\r\n        return _remove(set._inner, value);\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the value is in the set. O(1).\r\n     */\r\n    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {\r\n        return _contains(set._inner, value);\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of values in the set. O(1).\r\n     */\r\n    function length(Bytes32Set storage set) internal view returns (uint256) {\r\n        return _length(set._inner);\r\n    }\r\n\r\n   /**\r\n    * @dev Returns the value stored at position `index` in the set. O(1).\r\n    *\r\n    * Note that there are no guarantees on the ordering of values inside the\r\n    * array, and it may change when more values are added or removed.\r\n    *\r\n    * Requirements:\r\n    *\r\n    * - `index` must be strictly less than {length}.\r\n    */\r\n    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {\r\n        return _at(set._inner, index);\r\n    }\r\n\r\n    // AddressSet\r\n\r\n    struct AddressSet {\r\n        Set _inner;\r\n    }\r\n\r\n    /**\r\n     * @dev Add a value to a set. O(1).\r\n     *\r\n     * Returns true if the value was added to the set, that is if it was not\r\n     * already present.\r\n     */\r\n    function add(AddressSet storage set, address value) internal returns (bool) {\r\n        return _add(set._inner, bytes32(uint256(uint160(value))));\r\n    }\r\n\r\n    /**\r\n     * @dev Removes a value from a set. O(1).\r\n     *\r\n     * Returns true if the value was removed from the set, that is if it was\r\n     * present.\r\n     */\r\n    function remove(AddressSet storage set, address value) internal returns (bool) {\r\n        return _remove(set._inner, bytes32(uint256(uint160(value))));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the value is in the set. O(1).\r\n     */\r\n    function contains(AddressSet storage set, address value) internal view returns (bool) {\r\n        return _contains(set._inner, bytes32(uint256(uint160(value))));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of values in the set. O(1).\r\n     */\r\n    function length(AddressSet storage set) internal view returns (uint256) {\r\n        return _length(set._inner);\r\n    }\r\n\r\n   /**\r\n    * @dev Returns the value stored at position `index` in the set. O(1).\r\n    *\r\n    * Note that there are no guarantees on the ordering of values inside the\r\n    * array, and it may change when more values are added or removed.\r\n    *\r\n    * Requirements:\r\n    *\r\n    * - `index` must be strictly less than {length}.\r\n    */\r\n    function at(AddressSet storage set, uint256 index) internal view returns (address) {\r\n        return address(uint160(uint256(_at(set._inner, index))));\r\n    }\r\n\r\n\r\n    // UintSet\r\n\r\n    struct UintSet {\r\n        Set _inner;\r\n    }\r\n\r\n    /**\r\n     * @dev Add a value to a set. O(1).\r\n     *\r\n     * Returns true if the value was added to the set, that is if it was not\r\n     * already present.\r\n     */\r\n    function add(UintSet storage set, uint256 value) internal returns (bool) {\r\n        return _add(set._inner, bytes32(value));\r\n    }\r\n\r\n    /**\r\n     * @dev Removes a value from a set. O(1).\r\n     *\r\n     * Returns true if the value was removed from the set, that is if it was\r\n     * present.\r\n     */\r\n    function remove(UintSet storage set, uint256 value) internal returns (bool) {\r\n        return _remove(set._inner, bytes32(value));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the value is in the set. O(1).\r\n     */\r\n    function contains(UintSet storage set, uint256 value) internal view returns (bool) {\r\n        return _contains(set._inner, bytes32(value));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of values on the set. O(1).\r\n     */\r\n    function length(UintSet storage set) internal view returns (uint256) {\r\n        return _length(set._inner);\r\n    }\r\n\r\n   /**\r\n    * @dev Returns the value stored at position `index` in the set. O(1).\r\n    *\r\n    * Note that there are no guarantees on the ordering of values inside the\r\n    * array, and it may change when more values are added or removed.\r\n    *\r\n    * Requirements:\r\n    *\r\n    * - `index` must be strictly less than {length}.\r\n    */\r\n    function at(UintSet storage set, uint256 index) internal view returns (uint256) {\r\n        return uint256(_at(set._inner, index));\r\n    }\r\n}\r\n"
    },
    "@openzeppelin/contracts/utils/EnumerableMap.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\n/**\r\n * @dev Library for managing an enumerable variant of Solidity's\r\n * https://solidity.readthedocs.io/en/latest/types.html#mapping-types[`mapping`]\r\n * type.\r\n *\r\n * Maps have the following properties:\r\n *\r\n * - Entries are added, removed, and checked for existence in constant time\r\n * (O(1)).\r\n * - Entries are enumerated in O(n). No guarantees are made on the ordering.\r\n *\r\n * ```\r\n * contract Example {\r\n *     // Add the library methods\r\n *     using EnumerableMap for EnumerableMap.UintToAddressMap;\r\n *\r\n *     // Declare a set state variable\r\n *     EnumerableMap.UintToAddressMap private myMap;\r\n * }\r\n * ```\r\n *\r\n * As of v3.0.0, only maps of type `uint256 -> address` (`UintToAddressMap`) are\r\n * supported.\r\n */\r\nlibrary EnumerableMap {\r\n    // To implement this library for multiple types with as little code\r\n    // repetition as possible, we write it in terms of a generic Map type with\r\n    // bytes32 keys and values.\r\n    // The Map implementation uses private functions, and user-facing\r\n    // implementations (such as Uint256ToAddressMap) are just wrappers around\r\n    // the underlying Map.\r\n    // This means that we can only create new EnumerableMaps for types that fit\r\n    // in bytes32.\r\n\r\n    struct MapEntry {\r\n        bytes32 _key;\r\n        bytes32 _value;\r\n    }\r\n\r\n    struct Map {\r\n        // Storage of map keys and values\r\n        MapEntry[] _entries;\r\n\r\n        // Position of the entry defined by a key in the `entries` array, plus 1\r\n        // because index 0 means a key is not in the map.\r\n        mapping (bytes32 => uint256) _indexes;\r\n    }\r\n\r\n    /**\r\n     * @dev Adds a key-value pair to a map, or updates the value for an existing\r\n     * key. O(1).\r\n     *\r\n     * Returns true if the key was added to the map, that is if it was not\r\n     * already present.\r\n     */\r\n    function _set(Map storage map, bytes32 key, bytes32 value) private returns (bool) {\r\n        // We read and store the key's index to prevent multiple reads from the same storage slot\r\n        uint256 keyIndex = map._indexes[key];\r\n\r\n        if (keyIndex == 0) { // Equivalent to !contains(map, key)\r\n            map._entries.push(MapEntry({ _key: key, _value: value }));\r\n            // The entry is stored at length-1, but we add 1 to all indexes\r\n            // and use 0 as a sentinel value\r\n            map._indexes[key] = map._entries.length;\r\n            return true;\r\n        } else {\r\n            map._entries[keyIndex - 1]._value = value;\r\n            return false;\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev Removes a key-value pair from a map. O(1).\r\n     *\r\n     * Returns true if the key was removed from the map, that is if it was present.\r\n     */\r\n    function _remove(Map storage map, bytes32 key) private returns (bool) {\r\n        // We read and store the key's index to prevent multiple reads from the same storage slot\r\n        uint256 keyIndex = map._indexes[key];\r\n\r\n        if (keyIndex != 0) { // Equivalent to contains(map, key)\r\n            // To delete a key-value pair from the _entries array in O(1), we swap the entry to delete with the last one\r\n            // in the array, and then remove the last entry (sometimes called as 'swap and pop').\r\n            // This modifies the order of the array, as noted in {at}.\r\n\r\n            uint256 toDeleteIndex = keyIndex - 1;\r\n            uint256 lastIndex = map._entries.length - 1;\r\n\r\n            // When the entry to delete is the last one, the swap operation is unnecessary. However, since this occurs\r\n            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.\r\n\r\n            MapEntry storage lastEntry = map._entries[lastIndex];\r\n\r\n            // Move the last entry to the index where the entry to delete is\r\n            map._entries[toDeleteIndex] = lastEntry;\r\n            // Update the index for the moved entry\r\n            map._indexes[lastEntry._key] = toDeleteIndex + 1; // All indexes are 1-based\r\n\r\n            // Delete the slot where the moved entry was stored\r\n            map._entries.pop();\r\n\r\n            // Delete the index for the deleted slot\r\n            delete map._indexes[key];\r\n\r\n            return true;\r\n        } else {\r\n            return false;\r\n        }\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the key is in the map. O(1).\r\n     */\r\n    function _contains(Map storage map, bytes32 key) private view returns (bool) {\r\n        return map._indexes[key] != 0;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of key-value pairs in the map. O(1).\r\n     */\r\n    function _length(Map storage map) private view returns (uint256) {\r\n        return map._entries.length;\r\n    }\r\n\r\n   /**\r\n    * @dev Returns the key-value pair stored at position `index` in the map. O(1).\r\n    *\r\n    * Note that there are no guarantees on the ordering of entries inside the\r\n    * array, and it may change when more entries are added or removed.\r\n    *\r\n    * Requirements:\r\n    *\r\n    * - `index` must be strictly less than {length}.\r\n    */\r\n    function _at(Map storage map, uint256 index) private view returns (bytes32, bytes32) {\r\n        require(map._entries.length > index, \"EnumerableMap: index out of bounds\");\r\n\r\n        MapEntry storage entry = map._entries[index];\r\n        return (entry._key, entry._value);\r\n    }\r\n\r\n    /**\r\n     * @dev Tries to returns the value associated with `key`.  O(1).\r\n     * Does not revert if `key` is not in the map.\r\n     */\r\n    function _tryGet(Map storage map, bytes32 key) private view returns (bool, bytes32) {\r\n        uint256 keyIndex = map._indexes[key];\r\n        if (keyIndex == 0) return (false, 0); // Equivalent to contains(map, key)\r\n        return (true, map._entries[keyIndex - 1]._value); // All indexes are 1-based\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the value associated with `key`.  O(1).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `key` must be in the map.\r\n     */\r\n    function _get(Map storage map, bytes32 key) private view returns (bytes32) {\r\n        uint256 keyIndex = map._indexes[key];\r\n        require(keyIndex != 0, \"EnumerableMap: nonexistent key\"); // Equivalent to contains(map, key)\r\n        return map._entries[keyIndex - 1]._value; // All indexes are 1-based\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {_get}, with a custom error message when `key` is not in the map.\r\n     *\r\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\r\n     * message unnecessarily. For custom revert reasons use {_tryGet}.\r\n     */\r\n    function _get(Map storage map, bytes32 key, string memory errorMessage) private view returns (bytes32) {\r\n        uint256 keyIndex = map._indexes[key];\r\n        require(keyIndex != 0, errorMessage); // Equivalent to contains(map, key)\r\n        return map._entries[keyIndex - 1]._value; // All indexes are 1-based\r\n    }\r\n\r\n    // UintToAddressMap\r\n\r\n    struct UintToAddressMap {\r\n        Map _inner;\r\n    }\r\n\r\n    /**\r\n     * @dev Adds a key-value pair to a map, or updates the value for an existing\r\n     * key. O(1).\r\n     *\r\n     * Returns true if the key was added to the map, that is if it was not\r\n     * already present.\r\n     */\r\n    function set(UintToAddressMap storage map, uint256 key, address value) internal returns (bool) {\r\n        return _set(map._inner, bytes32(key), bytes32(uint256(uint160(value))));\r\n    }\r\n\r\n    /**\r\n     * @dev Removes a value from a set. O(1).\r\n     *\r\n     * Returns true if the key was removed from the map, that is if it was present.\r\n     */\r\n    function remove(UintToAddressMap storage map, uint256 key) internal returns (bool) {\r\n        return _remove(map._inner, bytes32(key));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns true if the key is in the map. O(1).\r\n     */\r\n    function contains(UintToAddressMap storage map, uint256 key) internal view returns (bool) {\r\n        return _contains(map._inner, bytes32(key));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of elements in the map. O(1).\r\n     */\r\n    function length(UintToAddressMap storage map) internal view returns (uint256) {\r\n        return _length(map._inner);\r\n    }\r\n\r\n   /**\r\n    * @dev Returns the element stored at position `index` in the set. O(1).\r\n    * Note that there are no guarantees on the ordering of values inside the\r\n    * array, and it may change when more values are added or removed.\r\n    *\r\n    * Requirements:\r\n    *\r\n    * - `index` must be strictly less than {length}.\r\n    */\r\n    function at(UintToAddressMap storage map, uint256 index) internal view returns (uint256, address) {\r\n        (bytes32 key, bytes32 value) = _at(map._inner, index);\r\n        return (uint256(key), address(uint160(uint256(value))));\r\n    }\r\n\r\n    /**\r\n     * @dev Tries to returns the value associated with `key`.  O(1).\r\n     * Does not revert if `key` is not in the map.\r\n     *\r\n     * _Available since v3.4._\r\n     */\r\n    function tryGet(UintToAddressMap storage map, uint256 key) internal view returns (bool, address) {\r\n        (bool success, bytes32 value) = _tryGet(map._inner, bytes32(key));\r\n        return (success, address(uint160(uint256(value))));\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the value associated with `key`.  O(1).\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `key` must be in the map.\r\n     */\r\n    function get(UintToAddressMap storage map, uint256 key) internal view returns (address) {\r\n        return address(uint160(uint256(_get(map._inner, bytes32(key)))));\r\n    }\r\n\r\n    /**\r\n     * @dev Same as {get}, with a custom error message when `key` is not in the map.\r\n     *\r\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\r\n     * message unnecessarily. For custom revert reasons use {tryGet}.\r\n     */\r\n    function get(UintToAddressMap storage map, uint256 key, string memory errorMessage) internal view returns (address) {\r\n        return address(uint160(uint256(_get(map._inner, bytes32(key), errorMessage))));\r\n    }\r\n}\r\n"
    },
    "@openzeppelin/contracts/utils/Strings.sol": {
      "content": "// SPDX-License-Identifier: MIT\r\n\r\npragma solidity >=0.6.0 <0.8.0;\r\n\r\n/**\r\n * @dev String operations.\r\n */\r\nlibrary Strings {\r\n    /**\r\n     * @dev Converts a `uint256` to its ASCII `string` representation.\r\n     */\r\n    function toString(uint256 value) internal pure returns (string memory) {\r\n        // Inspired by OraclizeAPI's implementation - MIT licence\r\n        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol\r\n\r\n        if (value == 0) {\r\n            return \"0\";\r\n        }\r\n        uint256 temp = value;\r\n        uint256 digits;\r\n        while (temp != 0) {\r\n            digits++;\r\n            temp /= 10;\r\n        }\r\n        bytes memory buffer = new bytes(digits);\r\n        uint256 index = digits - 1;\r\n        temp = value;\r\n        while (temp != 0) {\r\n            buffer[index--] = bytes1(uint8(48 + temp % 10));\r\n            temp /= 10;\r\n        }\r\n        return string(buffer);\r\n    }\r\n}\r\n"
    }
  },
  "settings": {
    "optimizer": {
      "enabled": true,
      "runs": 200
    },
    "outputSelection": {
      "*": {
        "*": [
          "evm.bytecode",
          "evm.deployedBytecode",
          "abi"
        ]
      }
    }
  }
}}