code: def get_all(self, attrs: Iterable[FetchAttribute]) \
              -> Sequence[Tuple[FetchAttribute, MaybeBytes]]:
          
          ret: List[Tuple[FetchAttribute, MaybeBytes]] = []
          for attr in attrs:
              try:
                  ret.append((attr.for_response, self.get(attr)))
              except NotFetchable:
                  pass
          return ret
docs: Return a list of tuples containing the attribute iself and the bytes
          representation of that attribute from the message.
  
          Args:
              attrs: The fetch attributes.