public void TestNeuterUserCredentialsActuallyNeuters() { string inputXml = "<test><user>abc</user><password>123</password></test>"; config["neuterUserCredentials"] = "true"; objectUnderTest.NeuterUserCredentials(ref inputXml); Assert.That(inputXml.Contains("<user>xxxxxx</user>")); Assert.That(inputXml.Contains("<password>xxxxxxxx</password>")); }