public void ChangeCase()
{
AreEqual(new UString("Hello There!!", 3, 9).ToUpper(), (UString)"LO THERE!");
string s = "!HELLO THERE!";
AreEqual(new UString(s, 1, 11).ToUpper(), (UString)"HELLO THERE");
AreEqual(new UString(s, 1, 11).ToUpper().InternalString, s);
s = "!HELLO THERE, Sailor Joe Fitzgeraldsteinenberg!";
AreEqual(new UString(s, 1, 4).ToUpper().InternalString, "HELL");
AreEqual(new UString("ĈĥáráĉtérŜ!").ToUpper(), (UString)"ĈĤÁRÁĈTÉRŜ!");
}