code: func (w *Window) resize(x, y int) {
  	w.x = x
  	w.y = y
  	w.backingStore = make([]Cell, x*y)
  
  	// iterate over widgets
  	for _, widget := range w.widgets {
  		widget.Resize()
  	}
  }
docs: // resize sets new x and y maxima.
  // resize shall be called from queue context.