public void OnAttached_WhenCalled_SubscribesToKeyDownEvents()
        {
            //Arrange
            var classUnderTest = new AutoCompleteTextBoxCommandBehavior();
            var mock = Mock.Create<TextBox>(Behavior.CallOriginal);
            Mock.ArrangeSet(() => mock.KeyDown += null).IgnoreArguments().OccursOnce();

            //Act
            classUnderTest.Attach(mock);

            //Assert
            Mock.AssertAll(mock);
        }       
 public void PropertiesTest()
 {
     var vm = new AutoCompleteTextBoxCommandBehavior();
     TestsHelper.TestPublicDeclaredPropertiesGetSet(vm, true);
 }