docs: def guess_entity_type(self, entity_id: EntityId) -> Optional[EntityType]:
          r"""Guess :class:`~.entity.EntityType` from the given
          :class:`~.entity.EntityId`.  It could return :const:`None` when it
          fails to guess.
  
          .. note::
  
             It always fails to guess when :attr:`entity_type_guess`
             is configued to :const:`False`.
  
          :return: The guessed :class:`~.entity.EntityId`, or :const:`None`
                   if it fails to guess.
          :rtype: :class:`~typing.Optional`\ [:class:`~.entity.EntityType`]
  
          .. versionadded:: 0.2.0
  
          """
          if not self.entity_type_guess:
              return None
          if entity_id[0] == 'Q':
              return EntityType.item
          elif entity_id[0] == 'P':
              return EntityType.property
          return None