public async Task MulticastInterface_Set_Loopback_Succeeds()
{
// On Windows, we can apparently assume interface 1 is "loopback." On other platforms, this is not a
// valid assumption. We could maybe use NetworkInterface.LoopbackInterfaceIndex to get the index, but
// this would introduce a dependency on System.Net.NetworkInformation, which depends on System.Net.Sockets,
// which is what we're testing here.... So for now, we'll just assume "loopback == 1" and run this on
// Windows only.
await MulticastInterface_Set_Helper(1);
}