Spawns and initializes an XBoard engine.
        Returns a :class:`~chess.engine.SimpleEngine` instance.

def popen_xboard(cls, command: Union[str, List[str]], *, timeout: Optional[float] = 10.0, debug: bool = False, setpgrp: bool = False, **popen_args: Any) -> "SimpleEngine":
        """
        Spawns and initializes an XBoard engine.
        Returns a :class:`~chess.engine.SimpleEngine` instance.
        """
        return cls.popen(XBoardProtocol, command, timeout=timeout, debug=debug, setpgrp=setpgrp, **popen_args)