content: /// Banner Size of Google Ad Manger.
  class DFPAdSize {
    final String _value;
    final double width;
    final double height;
  
    const DFPAdSize.custom({double width = 320, double height = 50})
        : this._internal("CUSTOM", width: width, height: height);
  
    const DFPAdSize._internal(this._value, {this.width, this.height});
  
    toString() => _value;
  
    static const FULL_WIDTH = -1.0;
    static const AUTO_HEIGHT = -2.0;
  
    static const BANNER =
        const DFPAdSize._internal('BANNER', width: 320, height: 50);
    static const FULL_BANNER =
        const DFPAdSize._internal('FULL_BANNER', width: 468, height: 60);
    static const LARGE_BANNER =
        const DFPAdSize._internal('LARGE_BANNER', width: 320, height: 100);
    static const LEADERBOARD =
        const DFPAdSize._internal('LEADERBOARD', width: 720, height: 90);
    static const MEDIUM_RECTANGLE =
        const DFPAdSize._internal('MEDIUM_RECTANGLE', width: 300, height: 250);
    static const SMART_BANNER = const DFPAdSize._internal('SMART_BANNER',
        width: FULL_WIDTH, height: AUTO_HEIGHT);
  }
  