code: func ForwardKey(k Key) {
  	if k.Window == nil {
  		return
  	}
  	k.Window.KeyHandler(windower2window[k.Window], k)
  }
docs: // ForwardKey must be called from the application to route key strokes to
  // windows.  The life cycle of keystrokes is as follows: widgets -> global
  // application context -> window.  Care must be taken in the application to not
  // rely on keystrokes that widgets may use.