code: public InvokeCallback sendRpcWithEndpoint(String endpoint, String service, String method, Object... args) {
          RemotingMessage message = createRemotingMessage(endpoint, service, method, args);
          Invoke invoke = createAmf3InvokeSkeleton(null, message);
          InvokeCallback callback = getInvokeCallback(invoke.getInvokeId());
  
          send(invoke);
          return callback;
      }
docs: Send a remote procedure call.
  @param endpoint The endpoint of the call
  @param service The service handling the call
  @param method The method to call
  @param args Optional args to the call
  @return The callback getting called once the rpc returns a result