docs: def query(cls, index_name=None, filter_builder=None,
                scan_index_forward=None, limit=None, **key_conditions):
          """High level query API.
  
          :param key_filter: key conditions of the query.
          :type key_filter: :class:`collections.Mapping`
          :param filter_builder: filter expression builder.
          :type filter_builder: :class:`~bynamodb.filterexps.Operator`
          """
          query_kwargs = {
              'key_conditions': build_condition(key_conditions, KEY_CONDITIONS),
              'index_name': index_name,
              'scan_index_forward': scan_index_forward,
              'limit': limit
          }
          if filter_builder:
              cls._build_filter_expression(filter_builder, query_kwargs)
          return ResultSet(cls, 'query', query_kwargs)