public void MinimumViableInterface_Guid_ReturnsExpectedResult() { var cacheKey = "SomethingInTheCache"; var expectedResult = Guid.NewGuid().ToString(); var mockedCache = MockFactory.CreateMockedCachingService(); var actualResult = mockedCache.GetOrAdd(cacheKey, () => expectedResult, DateTimeOffset.Now.AddMinutes(30)); Assert.AreSame(expectedResult, actualResult); }