This function is used to check `username` and `password` in case that
    :attr:`.settings.PRIVATE_INDEX` is set to ``True`` (default is ``False``).

def check_auth(username, password):
    """
    This function is used to check `username` and `password` in case that
    :attr:`.settings.PRIVATE_INDEX` is set to ``True`` (default is ``False``).
    """
    return (username == settings.PRIVATE_INDEX_USERNAME and
            settings.PRIVATE_INDEX_PASSWORD and
            password == settings.PRIVATE_INDEX_PASSWORD)