public void DeactivateThrows()
        {
            IRegion region = new AllActiveRegion();
            var view = new object();
            region.Add(view);

            region.Deactivate(view);
        }
        public void AddingViewsToRegionMarksThemAsActive()
        {
            IRegion region = new AllActiveRegion();
            var view = new object();

            region.Add(view);

            Assert.IsTrue(region.ActiveViews.Contains(view));
        }
        public async Task DeactivateThrows()
        {
            await ExecuteOnUIThread(() =>
                {
                    IRegion region = new AllActiveRegion();
                    var view = new object();
                    region.Add(view);

                    Assert.ThrowsException<InvalidOperationException>(() => region.Deactivate(view));
                });
        }
        public async Task AddingViewsToRegionMarksThemAsActive()
        {
            await ExecuteOnUIThread(() =>
                {
                    IRegion region = new AllActiveRegion();
                    var view = new object();

                    region.Add(view);

                    Assert.IsTrue(region.ActiveViews.Contains(view));
                });
        }