public async Task <Maybe <AppUser> > SearchByNormalizedUserName(string normalizedUserName)
        {
            var searchAppUserByNameSpec = new SearchAppUserByNormalizedNameSpec(normalizedUserName);
            var foundAppUser            = await _appUserRepository.LoadSingleAsync(searchAppUserByNameSpec);

            return(MaybeFactory.CreateFromNullable(foundAppUser));
        }
        public async Task <Maybe <AppUser> > SearchByIdAsync(string userId)
        {
            var foundAppUser = await _appUserRepository.LoadByIdAsync(userId);

            return(MaybeFactory.CreateFromNullable(foundAppUser));
        }