public void TestHideTilesAndShuffleRandomiseTilesWithoutAddingOrRemoving()
        {
            PairsGameViewModel vm = new PairsGameViewModel(dependencyService);
            int tilesCount        = vm.PairsTileItems.Count;

            vm.HideExistingTilesAndShuffle();

            Assert.AreEqual(tilesCount, vm.PairsTileItems.Count);
        }
        public void TestHideTilesAndShuffleHidesTiles()
        {
            PairsGameViewModel vm = new PairsGameViewModel(dependencyService);

            vm.PairsTileItems[5].FrontShown = true;
            vm.RandomNumberGenerator        = x => 0; //change the random generator to not move tiles.


            vm.HideExistingTilesAndShuffle();

            Assert.IsFalse(vm.PairsTileItems[5].FrontShown);
        }