public void MainViewModelConstructorWithNullVersionCheckerExpectedThrowsArgumentNullException()
{
var mockEventAggregator = new Mock<IEventAggregator>();
var envRepo = new Mock<IEnvironmentRepository>();
envRepo.Setup(e => e.All()).Returns(new List<IEnvironmentModel>());
envRepo.Setup(e => e.Source).Returns(new Mock<IEnvironmentModel>().Object);
new MainViewModel(mockEventAggregator.Object, new Mock<IAsyncWorker>().Object, envRepo.Object, null);
}