public void GenericRetvalAsync() { var handler = CreateClass("MyService", "GenericRetvalAsync")(new[] { typeof(string), typeof(int) }); var pureRetval = new Dictionary <string, int> { { "one", 1 }, { "two", 2 } }; service.GenericRetvalAsync <string, int>().Returns(Task.FromResult(pureRetval)); var retvalCodec = codecContainer.GetManualCodecFor <Dictionary <string, int> >(); var expectedData = retvalCodec.EncodeSingle(pureRetval); var resultingTask = handler.Handle(service, null, 0); Assert.That(resultingTask.Result, Is.EqualTo(expectedData)); }