prepareRevertedRevision example

return $form;
  }

  /** * {@inheritdoc} */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    // The revision timestamp will be updated when the revision is saved. Keep     // the original one for the confirmation message.     $original_revision_timestamp = $this->revision->getRevisionCreationTime();

    $this->revision = $this->prepareRevertedRevision($this->revision, $form_state);
    $this->revision->revision_log = $this->t('Copy of the revision from %date.', ['%date' => $this->dateFormatter->format($original_revision_timestamp)]);
    $this->revision->setRevisionUserId($this->currentUser()->id());
    $this->revision->setRevisionCreationTime($this->time->getRequestTime());
    $this->revision->setChangedTime($this->time->getRequestTime());
    $this->revision->save();

    $this->logger('content')->info('@type: reverted %title revision %revision.', ['@type' => $this->revision->bundle(), '%title' => $this->revision->label(), '%revision' => $this->revision->getRevisionId()]);
    $this->messenger()
      ->addStatus($this->t('@type %title has been reverted to the revision from %revision-date.', [
        '@type' => node_get_type_label($this->revision),
        '%title' => $this->revision->label(),