public void Update(IViewModelObject sourceInstance)
        {
            NoteViewModel source = sourceInstance as NoteViewModel;

            if (source == null)
            {
                throw new ArgumentNullException("sourceInstance");
            }
            Name        = source.Name;
            Description = source.Description;
        }
        public void Update(IViewModelObject sourceInstance)
        {
            EventViewModel source = sourceInstance as EventViewModel;

            if (source == null)
            {
                throw new ArgumentNullException("sourceInstance");
            }
            Name = source.Name;
            Date = source.Date;
        }