public void TestStripInvalid()
{
Assert.AreEqual(null, XmlExtensions.StripInvalidCharsFromXml(null));
Assert.AreEqual("", "".StripInvalidCharsFromXml());
Assert.AreEqual("<normal>XML!</normal>", "<normal>XML!</normal>".StripInvalidCharsFromXml());
Assert.AreEqual("spaces\tabs\rand\n.~ all OK", "spaces\tabs\rand\n.~ all OK".StripInvalidCharsFromXml());
Assert.AreEqual("now try and or and how about ?", "now try \a and \0 or \v and how about \xFFFF?".StripInvalidCharsFromXml());
Assert.AreEqual("and of course", "\0and\xc of course\0".StripInvalidCharsFromXml());
}