def is_comment(txt):
    """
    This does not validate chars,    basically because it allows `quoted-pair`,    meaning it allows all valid chars    (``HTAB / SP / VCHAR``)

    :param txt:
    :return:
    """
    assert isinstance(txt, str)
    if not txt.startswith('(') and not txt.endswith(')'):
        return False
    return True
