'Has this HIT expired yet?'

def _has_expired(self):

    expired = False
    if hasattr(self, 'Expiration'):
        now = datetime.datetime.utcnow()
        expiration = datetime.datetime.strptime(self.Expiration, '%Y-%m-%dT%H:%M:%SZ')
        expired = (now >= expiration)
    else:
        raise ValueError('ERROR:    Request    for    expired    property,    but    no    Expiration    in    HIT!')
    return expired
