public static void setFullScreenMode(JFrame frame, boolean fullScreen) {
    if (X11 == null) return;

    if (fullScreen) {
      X11.sendClientMessage(frame, "set FullScreen mode", X11.NET_WM_STATE, NET_WM_STATE_ADD, X11.NET_WM_STATE_FULLSCREEN);
    }
    else {
      X11.sendClientMessage(frame, "reset FullScreen mode", X11.NET_WM_STATE, NET_WM_STATE_REMOVE, X11.NET_WM_STATE_FULLSCREEN);
    }
  }
public static void setFullScreenMode(JFrame frame, boolean fullScreen)