/**
  * Find backend user
  *
  * @param integer $userId
  * @return array
  */
 public function findBackendUser($userId)
 {
     $user = $this->backendUserRepository->findByUid((int) $userId);
     if ($user instanceof BackendUser) {
         if ($this->isAllowedUser($user) === false) {
             return null;
         }
         $mounts = $user->getDbMountPoints();
         foreach ($user->getBackendUserGroups() as $group) {
             $mounts = $this->getAllDatabaseMountsFromUserGroup($group, $mounts);
         }
         $user->setInheritedMountPoints($mounts);
     }
     return $user;
 }