@Test
    public void testDoExecuteParaIsBlankError() {
        ServerWebExchange exchange = getServerWebExchange();
        exchange.getAttributes().put(Constants.META_DATA, new MetaData());
        RuleData data = mock(RuleData.class);
        StepVerifier.create(grpcPlugin.doExecute(exchange, chain, selector, data)).expectSubscription().verifyComplete();
    }
The Test Case For {@link GrpcPlugin}.
shenyu-plugin/shenyu-plugin-proxy/shenyu-plugin-rpc/shenyu-plugin-grpc/src/test/java/org/apache/shenyu/plugin/grpc/GrpcPluginTest.java