private void invokeTwice(THttpService service1, THttpService service2) throws Exception {
        final HttpData content = HttpData.wrap(out.getArray(), 0, out.length());
        invoke0(service1, content, promise);
        invoke0(service2, content, promise2);
    }
This tests when multiple thrift service implementations, with same service method are added under
default("") service name then the thrift service that is added first should handle the request.
And also makes sure that adding a duplicate service does not break other services.
thrift/thrift0.13/src/test/java/com/linecorp/armeria/server/thrift/ThriftServiceTest.java