/// <summary>
 /// Reloads the test tree, creating new test branches if necessary
 /// </summary>
 public static void ReloadTests()
 {
     foreach (var t in RootTests.OfType <UnitTestGroup> ())
     {
         t.UpdateTests();
     }
 }
 /// <summary>
 /// For each node already in the test tree, it checks if there is any change. If there is, it reloads the test.
 /// </summary>
 public static Task RefreshTests(CancellationToken ct)
 {
     return(Task.WhenAll(RootTests.Select(t => t.Refresh(ct))));
 }