protected function setUpSession () {
		if ($this->session === NULL) {
			$sessionClass = $this->application->GetSessionClass();
			$selfClass = version_compare(PHP_VERSION, '5.5', '>') ? self::class : __CLASS__;
			$this->session = $sessionClass::GetNamespace($selfClass);
			$this->session->SetExpirationSeconds($this->sessionExpirationSeconds);
		}
	}