test = typeHelper(callback, test, FixedValue.class);
    static Class determineType(Callback callback) {        Class test = typeHelper(callback, null, NoOp.class);        test = typeHelper(callback, test, MethodInterceptor.class);        test = typeHelper(callback, test, InvocationHandler.class);        test = typeHelper(callback, test, LazyLoader.class);        test = typeHelper(callback, test, Dispatcher.class);        if (test == null) {            throw new IllegalStateException("Unknown callback " + callback.getClass());        }        return test;    }