code: func Initialize(xu *xgbutil.XUtil) {
  	// Listen to mapping notify events
  	xevent.MappingNotifyFun(updateMaps).Connect(xu, xevent.NoWindow)
  
  	// Give us an initial mapping state...
  	keyMap, modMap := MapsGet(xu)
  	KeyMapSet(xu, keyMap)
  	ModMapSet(xu, modMap)
  }
docs: // Initialize attaches the appropriate callbacks to make key bindings easier.
  // i.e., update state of the world on a MappingNotify.