public void TestHasWebsites() { Assert.IsNull(configuration.WebsitesDelegate); configuration.HasWebsites(x => x.Websites); Assert.IsNotNull(configuration.WebsitesDelegate); var instance = new TestDocument(); instance.Websites = new string[] { "value1", "value2" }; Assert.IsTrue(Object.ReferenceEquals(instance.Websites, configuration.WebsitesDelegate(instance))); }