Nette\Http\Session::setHandler PHP Method

    public function setHandler(\SessionHandlerInterface $handler)
    {
        if (self::$started) {
            throw new Nette\InvalidStateException('Unable to set handler when session has been started.');
        }
        $this->handler = $handler;
        return $this;
    }

 /**
  * @internal
  * @param Nette\Http\Session $session
  * @return RedisSessionHandler
  */
 public function bind(Nette\Http\Session $session)
 {
     $this->session = $session;
     $session->setHandler($this);
     return $this;
 }