code: public function plugin($name, array $options = null)
      {
          return $this->getHelperPluginManager()
                      ->setRenderer($this)
                      ->get($name, $options);
      }
docs: Get plugin instance, proxy to HelperPluginManager::get
  
  @param  string     $name Name of plugin to return
  @param  null|array $options Options to pass to plugin constructor (if not already instantiated)
  @return \Zend\View\Helper\AbstractHelper