retranslate example

$form_object = $form_state->getFormObject();
    $form_langcode = $form_object->getFormLangcode($form_state);
    $values = &$form_state->getValue('content_translation', []);

    $metadata = $this->manager->getTranslationMetadata($entity);
    $metadata->setAuthor(!empty($values['uid']) ? User::load($values['uid']) : User::load(0));
    $metadata->setPublished(!empty($values['status']));
    $metadata->setCreatedTime(!empty($values['created']) ? strtotime($values['created']) : REQUEST_TIME);

    $metadata->setOutdated(!empty($values['outdated']));
    if (!empty($values['retranslate'])) {
      $this->retranslate($entity, $form_langcode);
    }
  }

  /** * Form validation handler for ContentTranslationHandler::entityFormAlter(). * * Validates the submitted content translation metadata. */
  public function entityFormValidate($form, FormStateInterface $form_state) {
    if (!$form_state->isValueEmpty('content_translation')) {
      $translation = $form_state->getValue('content_translation');