public FilterSessionsViewModel(INavigation navigation)
            : base(navigation)
        {
            
            AllCategory = new Category
                {
                    Name = "All",
                    IsEnabled = true,
                    IsFiltered = Settings.ShowAllCategories
                };

            AllCategory.PropertyChanged += (sender, e) =>
            {
                if (e.PropertyName == "IsFiltered")
                    SetShowAllCategories(AllCategory.IsFiltered);
            };
              
        }
        void LoadCategories()
        {
            vm.LoadCategoriesAsync().ContinueWith((result) =>
                {
                    Device.BeginInvokeOnMainThread(()=>
                        {
                            var allCell = new CategoryCell
                            {
                                BindingContext = vm.AllCategory
                            };

                            TableSectionCategories.Add(allCell);

                            foreach (var item in vm.Categories)
                            {
                                TableSectionCategories.Add(new CategoryCell
                                    {
                                        BindingContext = item
                                    });
                            }

                            var color = Device.OS == TargetPlatform.Windows || Device.OS == TargetPlatform.WinPhone ? "#7635EB" : string.Empty;

                            showPast = new Category
                            {
                                Name = "Show Past Sessions",
                                IsEnabled = true,
                                ShortName = "Show Past Sessions",
                                Color = color

                            };

                            showFavorites = new Category
                            {
                                Name = "Show Favorites Only",
                                IsEnabled = true,
                                ShortName = "Show Favorites Only",
                                Color = color

                            };

                            TableSectionFilters.Add(new CategoryCell
                            {
                                BindingContext = showPast
                            });

                            TableSectionFilters.Add(new CategoryCell
                            {
                                BindingContext = showFavorites
                            });

                            //if end of evolve
                            if (DateTime.UtcNow > Settings.EndOfEvolve)
                                showPast.IsEnabled = false;

                            showPast.IsFiltered = Settings.Current.ShowPastSessions;
                            showFavorites.IsFiltered = Settings.Current.FavoritesOnly;

                        });
                });
        }