Persist the given block's header and uncles.

        Assumes all block transactions have been persisted already.

def persist_block(self,
                      block: 'BaseBlock'
                      ) -> Tuple[Tuple[Hash32, ...], Tuple[Hash32, ...]]:
        """
        Persist the given block's header and uncles.

        Assumes all block transactions have been persisted already.
        """
        with self.db.atomic_batch() as db:
            return self._persist_block(db, block)