src/Pair.sol:
  216      /// @return fractionalTokenAmount The amount of fractional tokens minted.
  217:     function wrap(uint256[] calldata tokenIds, bytes32[][] calldata proofs)
  218:         public
  219:         returns (uint256 fractionalTokenAmount)
  220:     {
  221:         // *** Checks *** //
  222: 
  223:         // check that wrapping is not closed
  224:         require(closeTimestamp == 0, "Wrap: closed");
  225: 
  226:         // check the tokens exist in the merkle root
  227:         _validateTokenIds(tokenIds, proofs);
  228: 
  229:         // *** Effects *** //
  230: 
  231:         // mint fractional tokens to sender
  232:         fractionalTokenAmount = tokenIds.length * ONE;
  233:         _mint(msg.sender, fractionalTokenAmount);
  234: 
  235:         // *** Interactions *** //
  236: 
  237:         // transfer nfts from sender
  238:         for (uint256 i = 0; i < tokenIds.length; i++) {
  239:             ERC721(nft).safeTransferFrom(msg.sender, address(this), tokenIds[i]);
  240:         }
  241: 
  242:         emit Wrap(tokenIds);
  243:     }
 /**
  * @notice Sends ERC20 tokens trapped in contract to external address
  * @dev Onlyowner is allowed to make this function call
  * @param account is the receiving address
  * @param externalToken is the token being sent
  * @param amount is the quantity being sent
  * @return boolean value indicating whether the operation succeeded.
  *
 */
  function rescueERC20(address account, address externalToken, uint256 amount) public onlyOwner returns (bool) {
    IERC20(externalToken).transfer(account, amount);
    return true;
  }
}
