code: func (w *Window) MROpt(flags, x, y, width, height int) {
  	// Make sure only x/y/width/height are used.
  	flags &= xproto.ConfigWindowX | xproto.ConfigWindowY |
  		xproto.ConfigWindowWidth | xproto.ConfigWindowHeight
  	w.Configure(flags, x, y, width, height, 0, 0)
  }
docs: // MROpt is like MoveResize, but exposes the X value mask so that any
  // combination of x/y/width/height can be set. It's a strictly convenience
  // function. (i.e., when you need to set 'y' and 'height' but not 'x' or
  // 'width'.)