code: func WmColormapWindowsGet(xu *xgbutil.XUtil,
  	win xproto.Window) ([]xproto.Window, error) {
  
  	return xprop.PropValWindows(xprop.GetProperty(xu, win,
  		"WM_COLORMAP_WINDOWS"))
  }
docs: // WM_COLORMAP_WINDOWS get