code: def get_filtered_keys(self, suffix, *args, **kwargs):
          
  
          accepted_key_types = kwargs.get('accepted_key_types', None)
  
          if accepted_key_types and 'set' not in accepted_key_types:
              raise ImplementationError(
                  '%s can only return keys of type "set"' % self.__class__.__name__
              )
  
          # special "in" case: we get n keys and make an unionstore with them then return this key
          if suffix == 'in':
  
              args = list(args)
              values = set(args.pop())
  
              if not values:
                  return []  # no keys
  
              in_keys = [
                  self.get_storage_key(transform_value=False, *(args+[value]))
                  for value in values
              ]
  
              tmp_key = unique_key(self.connection)
              self.connection.sunionstore(tmp_key, *in_keys)
  
              return [(tmp_key, 'set', True)]
  
          # do not transform because we already have the value we want to look for
          return [(self.get_storage_key(transform_value=False, *args), 'set', False)]
docs: Return the set used by the index for the given "value" (`args`)
  
          For the parameters, see ``BaseIndex.get_filtered_keys``