public void TestLookupCredentialNetworkCredential()
{
var cred = new NetworkCredential("user", "pass");
Assert.AreEqual(cred, cred.LookupCredential("localhost", 110, null, null));
Assert.AreEqual(cred, cred.LookupCredential("localhost", 143, null, null));
Assert.AreEqual(cred, cred.LookupCredential("localhost", 143, "user", null));
Assert.AreEqual(cred, cred.LookupCredential("localhost", 110, null, "+apop"));
Assert.AreEqual(cred, cred.LookupCredential("localhost", 143, "user", "digest-md5"));
}