code: func runKeyBindCallbacks(xu *xgbutil.XUtil, event interface{}, evtype int,
  	win xproto.Window, mods uint16, keycode xproto.Keycode) {
  
  	key := xgbutil.KeyKey{evtype, win, mods, keycode}
  	for _, cb := range keyCallbacks(xu, key) {
  		cb.Run(xu, event)
  	}
  }
docs: // runKeyBindCallbacks executes every callback corresponding to a
  // particular event/window/mod/key tuple.
  // This is exported for use in the keybind package. It should not be used.