public function switchToWindow($name = null) {
    $handles = $this->browser->windowHandles();
    if ($name === null) {
      //null means back to the main window
      return $this->browser->switchToWindow($handles[0]);
    }

    $windowHandle = $this->browser->windowHandle($name);
    if (!empty($windowHandle)) {
      $this->browser->switchToWindow($windowHandle);
    } else {
      throw new DriverException("Could not find window handle by a given window name: $name");
    }

  }