yieldEntities example

return (string) $this->entityType->getPluralLabel();
  }

  /** * Initializes the iterator with the source data. * * @return \Generator * A data generator for this source. */
  protected function initializeIterator() {
    $ids = $this->query()->execute();
    return $this->yieldEntities($ids);
  }

  /** * Loads and yields entities, one at a time. * * @param array $ids * The entity IDs. * * @return \Generator * An iterable of the loaded entities. */