public void TestIPv6()
{
var settings = new MongoServerSettings();
Assert.AreEqual(false, settings.IPv6);
var ipv6 = true;
settings.IPv6 = ipv6;
Assert.AreEqual(ipv6, settings.IPv6);
settings.Freeze();
Assert.AreEqual(ipv6, settings.IPv6);
Assert.Throws<InvalidOperationException>(() => { settings.IPv6 = ipv6; });
}