public Function<? super HttpService, ? extends HttpService> decorator(
                DependencyInjector dependencyInjector) {
            if (decoratorFactory != null) {
                @SuppressWarnings("unchecked")
                final DecoratorFactoryFunction<Annotation> factory = AnnotatedObjectFactory
                        .getInstance(decoratorFactory, DecoratorFactoryFunction.class, dependencyInjector);
                return factory.newDecorator(annotation);
            }
            assert decoratorAnnotation != null;
            return service -> service.decorate(AnnotatedObjectFactory.getInstance(
                    decoratorAnnotation, DecoratingHttpServiceFunction.class, dependencyInjector));
        }
An internal class to hold a decorator with its order.
core/src/main/java/com/linecorp/armeria/internal/server/annotation/DecoratorAnnotationUtil.java