code: func ModMapSet(xu *xgbutil.XUtil, modMapReply *xproto.GetModifierMappingReply) {
  	xu.Modmap = &xgbutil.ModifierMapping{modMapReply}
  }
docs: // ModMapSet updates XUtil.modmap.
  // This is exported for use in the keybind package. You probably shouldn't
  // use this. (You may need to use this if you're rolling your own event loop,
  // and still want to use the keybind package.)