public static function add($name, $value, $groupName = null)
 {
     SessionStorage::add(self::varName($name, $groupName), $value);
 }
 public function login($userLogin, $userPassword)
 {
     $user = $this->getUserByLoginAndPassword($userLogin, $userPassword);
     SessionStorage::add(self::$USER_VAR, $user);
     return $user;
 }