@Test
    public void testExecuteWithResult() {
        String response = "{}";
        exchange.getAttributes().put(Constants.RPC_RESULT, response);
        StepVerifier.create(rpcMessageWriter.writeWith(exchange, chain)).expectSubscription().verifyComplete();
    }
The Test Case For {@link RPCMessageWriter}.
shenyu-plugin/shenyu-plugin-response/src/test/java/org/apache/shenyu/plugin/response/strategy/RPCMessageWriterTest.java