//public async Task<User> GetUserRelatedActivity(string id)
        //{
        //    var user = await usersRepository.GetOne(id);

        //    return user.Entity;
        //}

        public async Task <Activity> Add(Activity activity)
        {
            var result = await activityRepository.AddOne(activity);

            //TODO return created activity!?
            return(activity);
        }