code: func (user *User) IsPrivateStarted() bool {
  	err := user.ctx.Db().C("messages").Find(bson.M{"chatid": user.ID, "botid": user.ctx.Bot().ID, "fromid": user.ID}).Select(bson.M{"_id": 1}).One(nil)
  	if err == nil{
  		return true
  	}
  	return false
  }
docs: // IsPrivateStarted indicates if user started the private dialog with a bot (e.g. pressed the start button)