public function listen(Manager $manager)
 {
     $manager->listen('\\OC\\User', 'postDelete', [$this->userMountCache, 'removeUserMounts']);
 }
 /**
  * @param string $scope
  * @param string $method
  * @param callable $callback
  */
 public function listen($scope, $method, $callback)
 {
     $this->manager->listen($scope, $method, $callback);
 }