/**
 * 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 disabling blocks with missing condition contexts. Note: The
  // block itself is in a state which is valid at that point.
  // @see block_update_8001()
  // @see block_post_update_disable_blocks_with_missing_contexts()
  $block_update_8001 = \Drupal::keyValue('update_backup')->get('block_update_8001', []);

  $block_ids = array_keys($block_update_8001);
  $block_storage = \Drupal::entityManager()->getStorage('block');
  $blocks = $block_storage->loadMultiple($block_ids);
  /** @var $blocks \Drupal\block\BlockInterface[] */
  foreach ($blocks as $block) {
    // This block has had conditions removed due to an inability to resolve
    // contexts in block_update_8001() so disable it.

    // Disable currently enabled blocks.
    if ($block_update_8001[$block->id()]['status']) {
      $block->setStatus(FALSE);
      $block->save();
    }
  }

  return $result;
}