code: def _merge_chunk(self, value):
          
          current_column = len(self._current_row)
          field = self.fields[current_column]
          merged = _merge_by_type(self._pending_chunk, value, field.type)
          self._pending_chunk = None
          return merged
docs: Merge pending chunk with next value.
  
          :type value: :class:`~google.protobuf.struct_pb2.Value`
          :param value: continuation of chunked value from previous
                        partial result set.
  
          :rtype: :class:`~google.protobuf.struct_pb2.Value`
          :returns: the merged value