@classmethod
def match_header(cls, header):
    """
        Matches any extension HDU that is not one of the standard extension HDU
        types.
        """
    card = header.cards[0]
    xtension = card.value
    if isinstance(xtension, str):
        xtension = xtension.rstrip()
    standard_xtensions = 'IMAGE', 'TABLE', 'BINTABLE', 'A3DTABLE'
    return card.keyword == 'XTENSION' and xtension not in standard_xtensions
