/**
 * Implements hook_post_update_NAME().
 */
function {{ machine_name }}_post_update_NAME(&$sandbox) {
  // Example of updating some content.
  $node = \Drupal\node\Entity\Node::load(123);
  $node->setTitle('foo');
  $node->save();

  $result = t('Node %nid saved', ['%nid' => $node->id()]);

  // Example of updating some config.
  if (\Drupal::moduleHandler()->moduleExists('taxonomy')) {
    // Update the dependencies of all Vocabulary configuration entities.
    \Drupal::classResolver(\Drupal\Core\Config\Entity\ConfigEntityUpdater::class)->update($sandbox, 'taxonomy_vocabulary');
  }

  return $result;
}