code: def hscan(self, key, cursor=0, match=None, count=None):
          
          args = [key, cursor]
          match is not None and args.extend([b'MATCH', match])
          count is not None and args.extend([b'COUNT', count])
          fut = self.execute(b'HSCAN', *args)
          return wait_convert(fut, _make_pairs)
docs: Incrementally iterate hash fields and associated values.