def parse_known_and_unknown_args(
        self,
        args: Sequence[str | os.PathLike[str]],
        namespace: argparse.Namespace | None = None,
    ) -> tuple[argparse.Namespace, list[str]]:
        """Parse the known arguments at this point, and also return the
        remaining unknown arguments.

        :returns:
            A tuple containing an argparse namespace object for the known
            arguments, and a list of the unknown arguments.
        """
        optparser = self._getparser()
        strargs = [os.fspath(x) for x in args]
        return optparser.parse_known_args(strargs, namespace=namespace)
Parse the known arguments at this point, and also return the
        remaining unknown arguments.

        :returns:
            A tuple containing an argparse namespace object for the known
            arguments, and a list of the unknown arguments.
        
src/_pytest/config/argparsing.py