code: def _load_blocks(self, blocks: List[Tuple[Key, Any]]) -> List[TimeAggregate]:
          
          return [
              TypeLoader.load_item(self._schema.source.type)(self._schema.source, self._identity,
                                                             EvaluationContext()).run_restore(block)
              for (_, block) in blocks
          ]
docs: Converts [(Key, block)] to [BlockAggregate]
          :param blocks: List of (Key, block) blocks.
          :return: List of BlockAggregate