public void AllChildControlsLoopThroughEachChildControlsInControlCollectionTree()
        {
            var page = new Page();
            var controlCollection = new ControlCollection(page);
            var control1 = new Control();
            var control2 = new Control();
            var childControl1 = new Control();
            var childControl2 = new Control();
            controlCollection.Add(control1);
            controlCollection.Add(control2);
            control2.Controls.Add(childControl1);
            control2.Controls.Add(childControl2);

            Assert.That(controlCollection.AllChildControls().Count(), Is.EqualTo(4));
        }