public void AttributeSafeWithInvalidArgumentsReturnsEmptyString() { var result = ExtensionMethods.AttributeSafe(null, null); Assert.AreEqual(string.Empty, result); var elem = CreateXml(); result = elem.AttributeSafe(null); Assert.AreEqual(string.Empty, result); result = elem.AttributeSafe(string.Empty); Assert.AreEqual(string.Empty, result); result = elem.AttributeSafe("y"); Assert.AreEqual(string.Empty, result); }