private function saveReferrer(ServerRequestInterface $request)
    {
        Respond::session()->set(self::REFERRER, $request->getUri()->__toString());
    }
private function saveReferrer(ServerRequestInterface $request)
    {
        Respond::session()->set(self::REFERRER, $request->getUri()->__toString());
    }
private function saveReferrer ( ServerRequestInterface $ request ) { Respond :: session ( ) -> set ( self :: REFERRER , $ request -> getUri ( ) -> __toString ( ) ) ; }
saves the referrer uri to session.

@param ServerRequestInterface $request
saves the referrer uri to session .