private void ObjectInvariant()
{
Contract.Invariant(Matcher != null);
Contract.Invariant(Responder != null);
Contract.Invariant(Responder.GetType().GetTypeInfo().GetCustomAttributes <ResponderAttribute>().Any());
Contract.Invariant(Endpoint != null);
Contract.Invariant(EndpointAttribute != null);
Contract.Invariant(Endpoint.GetCustomAttributes <EndpointAttribute>().Contains(EndpointAttribute));
}