/// <summary>Adds references to [ViewTestClass]'s from the given assembly.</summary>
        /// <param name="assembly">The assembly to load from.</param>
        /// <param name="xapFileName">The name of the XAP file containing the class.</param>
        /// <returns>The number of classes found within the assembly.</returns>
        public int AddFromAssembly(Assembly assembly, string xapFileName)
        {
            // Create corresponding set of models and add to 'Classes' property.
            var list = new List<ViewTestClass>();
            foreach (var type in assembly.GetViewTestClasses())
            {
                list.Add(ViewTestClass.GetSingleton(type, xapFileName));
            }
            Classes.AddRange(list);

            // Finish up.
            var count = list.Count;
            if (count > 0) OnPropertyChanged(PropClasses);
            return count;
        }