Prado\Web\THttpRequest::getUrlReferrer PHP Method

    public function getUrlReferrer()
    {
        return isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : null;
    }

 public function testGetUrlReferrer()
 {
     $request = new THttpRequest();
     $request->init(null);
     self::assertEquals('https://github.com/pradosoft/prado4', $request->getUrlReferrer());
 }