code: def sort(self, *sorting, **kwargs):
          sorting_ = []
          for name, desc in sorting:
              field = self.meta.model._meta.fields.get(name)
              if field is None:
                  continue
              if desc:
                  field = field.desc()
              sorting_.append(field)
          if sorting_:
              return self.collection.order_by(*sorting_)
          return self.collection