code: func (c *Callbacks) OnCMsgPlaceDecalEvent(fn func(*dota.CMsgPlaceDecalEvent) error) {
  	c.onCMsgPlaceDecalEvent = append(c.onCMsgPlaceDecalEvent, fn)
  }
docs: // OnCMsgPlaceDecalEvent registers a callback for EBaseGameEvents_GE_PlaceDecalEvent