public async Task get_null_if_user_is_not_authenticated()
        {
            IHttpContextAccessor httpContextAccessor = new HttpContextAccessor();

            var provider = new HttpContextUserProvider(httpContextAccessor);

            (await provider.GetUserNameAsync()).Should().BeNull();
        }
        public async Task get_null_for_non_authenticated_user_with_default_name_claim()
        {
            var username = "******";

            var context = new DefaultHttpContext();

            context.User = GetNonAuthenticatedIdentityWithDefaultName(username);

            var httpContextAccessor = new HttpContextAccessor();

            httpContextAccessor.HttpContext = context;

            var provider = new HttpContextUserProvider(httpContextAccessor);

            (await provider.GetUserNameAsync()).Should().BeNull();
        }