private async Task OpenAsync()
{
await _dialogsService
.For <FullScreenImageViewModel>()
.WithParam(x => x.ImageUrl, "https://imageipsum.com/500x500")
.Navigate();
}
public void For_WhenCalledOnNull_ThrowsCorrectException()
{
IDialogsService dialogsService = null;
Assert.Throws <ArgumentNullException>(() => dialogsService.For <DialogViewModelStub>());
}