code: def _get_entity_pair(self, entity_id):
          
          entity = self._entities.get(entity_id)
          try:
              input_entity = utils.get_input_peer(entity)
          except TypeError:
              try:
                  input_entity = self._client._entity_cache[entity_id]
              except KeyError:
                  input_entity = None
  
          return entity, input_entity
docs: Returns ``(entity, input_entity)`` for the given entity ID.