contract FxERC721 is IFxERC721, ERC721 {
    address internal _fxManager;
    address internal _connectedToken;

    function initialize(
        address fxManager_,
        address connectedToken_,
        string memory name_,
        string memory symbol_
    ) public override {
        require(_fxManager == address(0x0) && _connectedToken == address(0x0), "Token is already initialized");
        _fxManager = fxManager_;
        _connectedToken = connectedToken_;

        // setup meta data
        setupMetaData(name_, symbol_);
    }

    // fxManager returns fx manager
    function fxManager() public view override returns (address) {
        return _fxManager;
    }

    // connectedToken returns root token
    function connectedToken() public view override returns (address) {
        return _connectedToken;
    }

    // setup name, symbol and decimals
    function setupMetaData(string memory _name, string memory _symbol) public {
        require(msg.sender == _fxManager, "Invalid sender");
        _setupMetaData(_name, _symbol);
    }

    function mint(
        address user,
        uint256 tokenId,
        bytes memory _data
    ) public override {
        require(msg.sender == _fxManager, "Invalid sender");
        _safeMint(user, tokenId, _data);
    }

    function burn(uint256 tokenId) public override {
        require(msg.sender == _fxManager, "Invalid sender");
        _burn(tokenId);
    }
}
/**
 * @title FxERC20 represents fx erc20
 */
function connectedToken() public view override returns (address) {
        return _connectedToken;
    }
// connectedToken returns root token