sanitizeWith ft fa (TagOpen name attributes)
  | ft name   = Just (TagOpen name (mapMaybe fa attributes))
  | otherwise = Nothing
sanitizeWith ft fa (TagOpen name attributes)
  | ft name   = Just (TagOpen name (mapMaybe fa attributes))
  | otherwise = Nothing
sanitizeWith ft fa (TagOpen name attributes)
  | ft name   = Just (TagOpen name (mapMaybe fa attributes))
  | otherwise = Nothing