code: func (c *Callbacks) OnCUserMessageVoiceMask(fn func(*dota.CUserMessageVoiceMask) error) {
  	c.onCUserMessageVoiceMask = append(c.onCUserMessageVoiceMask, fn)
  }
docs: // OnCUserMessageVoiceMask registers a callback for EBaseUserMessages_UM_VoiceMask