public function getDefaults()
  {
    return array(
      'android'     => false,
      'browser'     => self::BROWSER,
      'cookies'     => ( count( $_COOKIE ) > 0 ) ? true : false,
      'height'      => self::HEIGHT,
      'hidpi'       => ( array_key_exists( 'HTTP_DPR', $_SERVER ) ) ? $_SERVER[ 'HTTP_DPR' ] > 1 : false,
      'ios'         => false,
      'low_speed'   => false, // deprecated
      'low_battery' => false, // deprecated
      'metered'     => $this->getMeteredDefault(),
      'touch'       => self::TOUCH,
      'user-agent'  => $this->getUserAgentDefault(),
      'viewport'    => $this->getViewportDefault(),
      'width'       => self::WIDTH
    );
  }