public void ConvertBackTest()
 {
     const Visibility trueValue = Visibility.Collapsed;
     const Visibility falseValue = Visibility.Visible;
     var converter = new BooleanToVisibilityConverter(Visibility.Collapsed, Visibility.Visible, Visibility.Visible);
     converter.ConvertBack(trueValue, typeof(bool), null, null).ShouldEqual(true);
     converter.ConvertBack(falseValue, typeof(bool), null, null).ShouldEqual(false);
 }
 public void ConvertBackShouldThrowExceptionInvalidValue()
 {
     var converter = new BooleanToVisibilityConverter(Visibility.Collapsed, Visibility.Visible, Visibility.Visible);
     Action action = () => converter.ConvertBack(new object(), typeof (object), null, null);
     action.ShouldThrow();
 }