File: NTokenMoonBirds.sol
63:     function onERC721Received(
64:         address operator,
65:         address from,
66:         uint256 id,
67:         bytes memory
68:     ) external virtual override returns (bytes4) {
69:         // only accept MoonBird tokens
70:         require(msg.sender == _underlyingAsset, Errors.OPERATION_NOT_SUPPORTED);
71: 
72:         // if the operator is the pool, this means that the pool is transferring the token to this contract
73:         // which can happen during a normal supplyERC721 pool tx
74:         if (operator == address(POOL)) {
75:             return this.onERC721Received.selector;
76:         }
77: 
78:         // supply the received token to the pool and set it as collateral
79:         DataTypes.ERC721SupplyParams[]
80:             memory tokenData = new DataTypes.ERC721SupplyParams[](1);
81: 
82:         tokenData[0] = DataTypes.ERC721SupplyParams({
83:             tokenId: id,
84:             useAsCollateral: true
85:         });
86: 
87:         POOL.supplyERC721FromNToken(_underlyingAsset, tokenData, from);
88: 
89:         return this.onERC721Received.selector;
90:     }
function onERC721Received(
	address operator,
	address from,
	uint256 id,
	bytes memory
) external virtual override returns (bytes4) {
-	// only accept MoonBird tokens
-	require(msg.sender == _underlyingAsset, Errors.OPERATION_NOT_SUPPORTED);

	// if the operator is the pool, this means that the pool is transferring the token to this contract
	// which can happen during a normal supplyERC721 pool tx
	if (operator == address(POOL)) {
		return this.onERC721Received.selector;
	}

+	if msg.sender == _underlyingAsset(
        // supply the received token to the pool and set it as collateral
        DataTypes.ERC721SupplyParams[]
            memory tokenData = new DataTypes.ERC721SupplyParams[](1);

        tokenData[0] = DataTypes.ERC721SupplyParams({
            tokenId: id,
            useAsCollateral: true
        });
+	)

	POOL.supplyERC721FromNToken(_underlyingAsset, tokenData, from);

	return this.onERC721Received.selector;
}
