Timeout calls to IBus.Send().Register()

NServiceBusTimeoutRegister.cs

// NOTE: There is a bug in NServiceBus where registered callbacks that are not invoked remain in a static dictionary.
var asyncResult = _bus.Send(message).Register(ar => { }, null);
if (!asyncResult.AsyncWaitHandle.WaitOne(_timeout))
{
    // Signal the async result so callback threads don't remain blocked
    ((EventWaitHandle)asyncResult.AsyncWaitHandle).Set();
    throw new OperationCanceledException();
}