code: def read_all_from_datastore(self):
      
      self._work = {}
      client = self._datastore_client
      parent_key = client.key(KIND_WORK_TYPE, self._work_type_entity_id)
      for entity in client.query_fetch(kind=KIND_WORK, ancestor=parent_key):
        work_id = entity.key.flat_path[-1]
        self.work[work_id] = dict(entity)
docs: Reads all work pieces from the datastore.