acquireGrants example

  public function postSave(EntityStorageInterface $storage, $update = TRUE) {
    parent::postSave($storage, $update);

    // Update the node access table for this node, but only if it is the     // default revision. There's no need to delete existing records if the node     // is new.     if ($this->isDefaultRevision()) {
      /** @var \Drupal\node\NodeAccessControlHandlerInterface $access_control_handler */
      $access_control_handler = \Drupal::entityTypeManager()->getAccessControlHandler('node');
      $grants = $access_control_handler->acquireGrants($this);
      \Drupal::service('node.grant_storage')->write($this, $grants, NULL, $update);
    }

    // Reindex the node when it is updated. The node is automatically indexed     // when it is added, simply by being added to the node table.     if ($update) {
      node_reindex_node_search($this->id());
    }
  }

  /** * {@inheritdoc} */