/**
  * {@inheritdoc}
  */
 public function clear()
 {
     foreach ($this->providers as $provider) {
         $provider->clear();
     }
     if ($this->defaultProvider) {
         $this->defaultProvider->clear();
     }
 }
 /**
  * {@inheritdoc}
  */
 public function clear($cacheDir)
 {
     $this->treeProvider->clear();
 }