public async Task Contains_TestAsync()
        {
            var userFilter = new UserFilter();
            var user       = await userFilter.GetUserAsync(app);

            var contains = await userCollection.Dispatcher.InvokeAsync(() => userCollection.Contains(user.ID));

            Assert.IsTrue(contains);
        }
 public void Contains()
 {
     users.Contains(string.Empty);
 }
 public static Task <bool> ContainsAsync(this IUserCollection userCollection, string userID)
 {
     return(userCollection.Dispatcher.InvokeAsync(() => userCollection.Contains(userID)));
 }