def _type_anotation_comment_exists(line_str: str) -> bool:
    """
    Get a boolean value whether type annotation comment exists
    in line or not.

    Parameters
    ----------
    line_str : str
        The target line string.

    Returns
    -------
    result : bool
        If exists, True will be set.
    """
    result: bool = '# type: ' in line_str
    return result