public void ContinueToMain(MainViewModel.SubView?subView = null)
        {
            if (MainViewModel == null)
            {
                MainViewModel = new MainViewModel();
            }
            if (subView.HasValue)
            {
                switch (subView.Value)
                {
                case MainViewModel.SubView.Auction: if (AuctionViewModel == null)
                    {
                        AuctionViewModel = new AuctionViewModelDesign();
                    }
                    break;

                case MainViewModel.SubView.Products: if (ProductsViewModel == null)
                    {
                        ProductsViewModel = new ProductsViewModelDesign();
                    }
                    break;
                }
            }
            RunOnUIThread(() => _navigator.NavigateToMainView(subView));
        }
        /* TODO: For each viewmodel, add a public property with a private setter like this:
         * public _VIEWNAME_ViewModel _VIEWNAME_ViewModel { get; private set; }
         * Note that the New-View and New-ViewModel commands add the above code automatically (see http://github.com/MacawNL/MvvmQuickCross#new-viewmodel). */

        public void ContinueToMain(MainViewModel.SubView?subView = null, bool skipNavigation = false)
        {
            if (MainViewModel == null)
            {
                MainViewModel = new MainViewModel();
            }
            if (subView.HasValue)
            {
                switch (subView.Value)
                {
                case MainViewModel.SubView.Auction: if (AuctionViewModel == null)
                    {
                        AuctionViewModel = new AuctionViewModelDesign();
                    }
                    break;

                case MainViewModel.SubView.Products: if (ProductsViewModel == null)
                    {
                        ProductsViewModel = new ProductsViewModelDesign();
                    }
                    break;
                }
            }
            if (!skipNavigation)
            {
                RunOnUIThread(() => _navigator.NavigateToMainView(CurrentNavigationContext, subView));
            }
        }