code: def _only_trashed(self, builder):
          
          model = builder.get_model()
  
          self.remove(builder, model)
  
          builder.get_query().where_not_null(model.get_qualified_deleted_at_column())
docs: The only-trashed extension.
  
          :param builder: The query builder
          :type builder: eloquent.orm.builder.Builder