/**
  * @param $alias
  *
  * @throws \InvalidArgumentException    When cant retrieve filter from service manager.
  *
  * @return mixed
  */
 public function get($alias)
 {
     if (parent::has($alias)) {
         return parent::get($alias);
     }
     $service = $this->serviceLocator;
     if (!$service->has($alias)) {
         throw new \InvalidArgumentException(sprintf('There is no "%s" filter in ZF2 service manager.', $alias));
     }
     $filter = $service->get($alias);
     if (!$filter instanceof FilterInterface) {
         $givenType = is_object($filter) ? get_class($filter) : gettype($filter);
         $message = 'Retrieved filter "%s" is not instanceof "Assetic\\Filter\\FilterInterface", but type was given %s';
         $message = sprintf($message, $alias, $givenType);
         throw new \InvalidArgumentException($message);
     }
     $this->set($alias, $filter);
     return $filter;
 }
 public function has($name)
 {
     return isset($this->mappings[$name]) || parent::has($name);
 }
 /**
  * Check filter exists
  *
  * @param  string $name
  * @return bool
  */
 public function has($name)
 {
     return array_key_exists($name, $this->mappings) || parent::has($name);
 }