code: def fetch_objects(self, oids):
          '''
          This methods is used to fetch models
          from a list of identifiers.
  
          Default implementation performs a bulk query on identifiers.
  
          Override this method to customize the objects retrieval.
          '''
          objects = self.model.objects.in_bulk(oids)
          if len(objects.keys()) != len(oids):
              non_existants = set(oids) - set(objects.keys())
              msg = _('Unknown identifiers: {identifiers}').format(
                  identifiers=', '.join(str(ne) for ne in non_existants))
              raise validators.ValidationError(msg)
  
          return [objects[id] for id in oidsf fetch_objects(self, oids):
          '''
          This methods is used to fetch models
          from a list of identifiers.
  
          Default implementation performs a bulk query on identifiers.
  
          Override this method to customize the objects retrieval.
          '''
          objects = self.model.objects.in_bulk(oids)
          if len(objects.keys()) != len(oids):
              non_existants = set(oids) - set(objects.keys())
              msg = _('Unknown identifiers: {identifiers}').format(
                  identifiers=', '.join(str(ne) for ne in non_existants))
              raise validators.ValidationError(msg)
  
          return [objects[id] for id in oids]
docs: This methods is used to fetch models
          from a list of identifiers.
  
          Default implementation performs a bulk query on identifiers.
  
          Override this method to customize the objects retrieval.