code: func (c *Callbacks) OnCDOTAUserMsg_ProjectionEvent(fn func(*dota.CDOTAUserMsg_ProjectionEvent) error) {
  	c.onCDOTAUserMsg_ProjectionEvent = append(c.onCDOTAUserMsg_ProjectionEvent, fn)
  }
docs: // OnCDOTAUserMsg_ProjectionEvent registers a callback for EDotaUserMessages_DOTA_UM_ProjectionEvent