code: def _indexes(self):
          
          if not self.indexable:
              return []
          if not self.index_classes:
              self.index_classes = self.get_default_indexes()[::1]
          if not self.index_classes:
              raise ImplementationError('%s field is indexable but has no indexes attached' %
                                        self.__class__.__name__)
  
          return [index_class(field=self) for index_class in self.index_classes]
docs: Instantiate the indexes only when asked
  
          Returns
          -------
          list
              An empty list if the field is not indexable, else a list of all indexes
              tied to the field.
              If no indexes where passed when creating the field, the default indexes
              from the field/model/database will be used.
              If still no index classes, it will raise
  
          Raises
          ------
          ImplementationError
              If no index classes available for this field