public ApplicationSpec addService(String protocol, String name) {
        if (!services.containsKey(protocol)) {
            services.put(protocol, new HashSet<String>());
        }
        services.get(protocol).add(name);
        return this;
    }
Adds a service name to the list of known services.

@param protocol The protocol for which to add the service.
@param name     The service to add.
@return This, to allow chaining.
messagebus/src/main/java/com/yahoo/messagebus/routing/ApplicationSpec.java