public virtual void ShouldHandleClearingTheSelectedIndicesProperty()
        {
            Accordion a = new Accordion();
            IList<int> original = a.SelectedIndices;
            bool exceptionThrown = false;

            try
            {
                a.SetValue(Accordion.SelectedIndicesProperty, null);
            }
            catch (InvalidOperationException)
            {
                exceptionThrown = true;
            }

            Assert.IsTrue(exceptionThrown);
            Assert.IsTrue(a.SelectedIndices.Count == 0);
            Assert.IsTrue(original == a.SelectedIndices);

            // reset test
            exceptionThrown = false;
            try
            {
                a.ClearValue(Accordion.SelectedIndicesProperty);
            }
            catch (InvalidOperationException)
            {
                exceptionThrown = true;
            }

            Assert.IsTrue(exceptionThrown);
            Assert.IsTrue(a.SelectedIndices.Count == 0);
            Assert.IsTrue(original == a.SelectedIndices);
        }