private function loadRevisions(array &$revisions, array &$options) {
    $options[self::DEFAULT_DIFF_TARGET] = $this->t('Open Y version');
    $revision_ids = $this->upgradeLogManager
      ->loggerEntityStorage
      ->revisionIds($this->entity);

    foreach ($revision_ids as $key => $revision_id) {
      $revision = $this->upgradeLogManager
        ->loggerEntityStorage
        ->loadRevision($revision_id);
      $options[$revision_id] = $this->t('Revision: @time', [
        '@time' => $this->dateFormatter->format($revision->getRevisionCreationTime()),
      ]);
      if ($revision->isDefaultRevision()) {
        $options[$revision_id] = $this->t('Current Revision');
      }
      $revisions[$revision_id] = $revision;
    }
  }