public void NavigateTo(IMenuViewItem item)
        {
            if (item == null) return;
            if (previousItem != null) previousItem.IsSelected = false;
            previousItem = item;
            item.IsSelected = true;

            this.commands.OpenView(item.ViewType);
        }
        public void NavigateTo(IMenuViewItem item)
        {
            if (item == null)
            {
                return;
            }
            if (previousItem != null)
            {
                previousItem.IsSelected = false;
            }
            previousItem    = item;
            item.IsSelected = true;

            this.commands.OpenView(item.ViewType);
        }