setCachedDefinitions example

protected function alterInfo($alter_hook) {
    $this->alterHook = $alter_hook;
  }

  /** * {@inheritdoc} */
  public function getDefinitions() {
    $definitions = $this->getCachedDefinitions();
    if (!isset($definitions)) {
      $definitions = $this->findDefinitions();
      $this->setCachedDefinitions($definitions);
    }
    return $definitions;
  }

  /** * {@inheritdoc} */
  public function clearCachedDefinitions() {
    if ($this->cacheBackend) {
      if ($this->cacheTags) {
        // Use the cache tags to clear the cache.