ServiceSpecification addExamples(ServiceSpecification spec) {
        final List<ServiceInfo> serviceWithExample =
                spec.services().stream().map(this::addServiceExamples).collect(toImmutableList());
        final Iterable<HttpHeaders> exampleHeaders =
                Iterables.concat(spec.exampleHeaders(),
                                 this.exampleHeaders.getOrDefault("", ImmutableListMultimap.of()).get(""));

        return new ServiceSpecification(serviceWithExample, spec.enums(), spec.structs(), spec.exceptions(),
                                        exampleHeaders, spec.docServiceRoute());
    }
Adds examples to the {@link ServiceSpecification} and {@link ServiceInfo} objects.
@param spec Spec itself.
@return new {@link ServiceSpecification} with examples.
core/src/main/java/com/linecorp/armeria/server/docs/ExampleSupport.java