public void AddAutofacMultitenantRequestServices_NullBuilder()
        {
            var mtc = new MultitenantContainer(Mock.Of <ITenantIdentificationStrategy>(), new ContainerBuilder().Build());

            Assert.Throws <ArgumentNullException>(() => AutofacMultitenantServiceCollectionExtensions.AddAutofacMultitenantRequestServices(null, () => mtc));
        }