Duplicated test scenario I would like to test

WpfViewModelFirst.Tests/MainWindowViewModelTests.cs

@@ -0,0 +1,34 @@
+using Moq;
+using WpfViewModelFirst.Part1;
+using WpfViewModelFirst.Part2;
+
+namespace WpfViewModelFirst.Tests
+{
+    public class MainWindowViewModelTests
+    {
+        [Fact]
+        public void Part1WillSetPart1ViewModelToCurrentViewModel()
+        {
+            Part1ViewModel part1ViewModel = new(() => _ = true);
+            Mock<IViewModelFactory> mockViewModelFactory = new Mock<IViewModelFactory>();
+            mockViewModelFactory.Setup(vmf => vmf.GetPart1ViewModel(It.IsAny<Action>()))
+                .Returns(part1ViewModel);
+            MainWindowViewModel main = new(mockViewModelFactory.Object);
+            main.Part1(null);
+            Assert.Equal(part1ViewModel, main.CurrentViewModel);
+        }
+        [Fact]
+        public void Part1CallbackIsSuccessfull()
+        {
+            Mock<IViewModelFactory> mockViewModelFactory = new Mock<IViewModelFactory>();
+            mockViewModelFactory.Setup(vmf => vmf.GetPart1ViewModel(It.IsAny<Action>()))
+                .Returns(() => new Part1ViewModel(() => Task.Delay(0)))
+                .Callback<Action>(c => c.Invoke());
+            mockViewModelFactory.Setup(vmf => vmf.GetPart2ViewModel())
+                .Returns(() => new Part2ViewModel());
+            MainWindowViewModel main = new(mockViewModelFactory.Object);
+            main.Part1(null);
+            Assert.IsType<Part2ViewModel>(main.CurrentViewModel);
+        }
+    }
+}