public void SubscriptionCache_CanBeCreated_IsCreated()
        {
            Mock <IConfigurationRepository> configurationRepository = new Mock <IConfigurationRepository>();

            var config = Options.Create(new ServiceSettings
            {
                CacheTimeout = 30
            });

            ISubscriptionCache <SubscriptionGroup> subscriptionCache = new SubscriptionCache(configurationRepository.Object, config);

            subscriptionCache.ShouldNotBeNull();
        }