def METHOD_NAME(requested: str) -> tuple[Path | None, int | None]:
    """Determine is the user requested string is a file.
    :param requested: The string requested at the ``:`` prompt
    :returns: None, None or file name and line number
    """
    parts = requested.rsplit(":", 1)
    possible_filename = Path(parts[0])
    if possible_filename.is_file():
        file_name = possible_filename
        try:
            line_number = int(parts[1:][0]) if parts[1:] else 0
        except ValueError:
            line_number = 0
        return file_name, line_number
    return None, None