tyThingParent_maybe (ATyCon tc)   = case tyConAssoc_maybe tc of
                                      Just cls -> Just (ATyCon (classTyCon cls))
                                      Nothing  -> Nothing
tyThingParent_maybe (ATyCon tc)   = case tyConAssoc_maybe tc of
                                      Just cls -> Just (ATyCon (classTyCon cls))
                                      Nothing  -> Nothing
tyThingParent_maybe (ATyCon tc)   = case tyConAssoc_maybe tc of
                                      Just cls -> Just (ATyCon (classTyCon cls))
                                      Nothing  -> Nothing