code: func (c *Callbacks) OnCDOTAUserMsg_BotChat(fn func(*dota.CDOTAUserMsg_BotChat) error) {
  	c.onCDOTAUserMsg_BotChat = append(c.onCDOTAUserMsg_BotChat, fn)
  }
docs: // OnCDOTAUserMsg_BotChat registers a callback for EDotaUserMessages_DOTA_UM_BotChat