code: func (c *Callbacks) OnCDOTAUserMsg_BeastChat(fn func(*dota.CDOTAUserMsg_BeastChat) error) {
  	c.onCDOTAUserMsg_BeastChat = append(c.onCDOTAUserMsg_BeastChat, fn)
  }
docs: // OnCDOTAUserMsg_BeastChat registers a callback for EDotaUserMessages_DOTA_UM_BeastChat