public static void Ctor_Tests()
        {
            string[] anArray = new string[] { "one", "two", "three", "four", "five" };
            ReadOnlyObservableCollection <string> readOnlyCol =
                new ReadOnlyObservableCollection <string>(new ObservableCollection <string>(anArray));
            IReadOnlyList_T_Test <string> helper = new IReadOnlyList_T_Test <string>(readOnlyCol, anArray);

            helper.InitialItems_Tests();
            IList <string> readOnlyColAsIList = readOnlyCol;

            Assert.True(readOnlyColAsIList.IsReadOnly, "ReadOnlyObservableCollection should be readOnly.");
        }