public CachingMongoDbClientStoreTests()
 {
     FakeFactory.Create(out _decorated, out _backgroundTaskStarter);
     _cache      = new FakeMemoryCache();
     _expiration = TimeSpan.FromSeconds(30);
     _sut        = new CachingMongoDbClientStore(_decorated, _cache, _expiration, _backgroundTaskStarter);
 }
            public async Task WhenExpirationIsZeroOrNegative_DoesNotUseCache_AndDelegatesToDecoratedInstance(int expirationSeconds)
            {
                var sut = new CachingMongoDbClientStore(_decorated, _cache, TimeSpan.FromSeconds(expirationSeconds), _backgroundTaskStarter);

                await sut.Get(_keyId);

                A.CallTo(() => _decorated.Get(_keyId))
                .MustHaveHappened();
                _cache.InternalData.Should().BeEmpty();
            }