protected function setHandler(ServerRequestInterface $request, $handler): ServerRequestInterface
    {
        return $request->withAttribute($this->attribute, $handler);
    }
protected function setHandler(ServerRequestInterface $request, $handler): ServerRequestInterface
    {
        return $request->withAttribute($this->attribute, $handler);
    }
protected function setHandler ( ServerRequestInterface $ request , $ handler ) : ServerRequestInterface { return $ request -> withAttribute ( $ this -> attribute , $ handler ) ; }
Set the handler reference on the request.

@param mixed $handler
Set the handler reference on the request .