@Test
    public void testExecute() {
        ServerWebExchange exchangeNoPath = MockServerWebExchange.from(MockServerHttpRequest.get("/test").build());
        exchangeNoPath.getAttributes().put(Constants.CONTEXT, mock(ShenyuContext.class));
        StepVerifier.create(nettyHttpClientPlugin.execute(exchangeNoPath, chain)).expectSubscription().verifyComplete();
        ServerWebExchange exchange = MockServerWebExchange.from(MockServerHttpRequest.post("/test")
                .header(HttpHeaderNames.CONNECTION.toString(), HttpHeaderValues.KEEP_ALIVE.toString())
                .body("test"));
        exchange.getAttributes().put(Constants.CONTEXT, mock(ShenyuContext.class));
        exchange.getAttributes().put(Constants.HTTP_URI, URI.create("/test"));

        StepVerifier.create(nettyHttpClientPlugin.execute(exchange, chain)).expectSubscription().verifyError();
    }
test case for NettyHttpClientPlugin {@link NettyHttpClientPlugin#execute(ServerWebExchange, ShenyuPluginChain)}.
shenyu-plugin/shenyu-plugin-httpclient/src/test/java/org/apache/shenyu/plugin/httpclient/NettyHttpClientPluginTest.java