code: func NewConversationWithVersion(v int) *Conversation {
  	var vv otrVersion
  
  	switch v {
  	case 2:
  		vv = otrV2{}
  	case 3:
  		vv = otrV3{}
  	}
  	return &Conversation{version: vv}
  }
docs: // NewConversationWithVersion creates a new conversation with the given version