static <A> A proxy(Class<A> intrface, final O target) {
   ret (A) java.lang.reflect.Proxy.newProxyInstance(intrface.getClassLoader(),
     new Class[] { intrface },
     new InvocationHandler {
       public O invoke(O proxy, Method method, O[] args) {
         ret call(target, method.getName(), unnull(args));
       }
     });
}