### Question:
ReferenceBuilder extends AbstractReferenceBuilder<ReferenceConfig, ReferenceBuilder<T>> { public ReferenceBuilder<T> addMethod(MethodConfig method) { if (this.methods == null) { this.methods = new ArrayList<>(); } this.methods.add(method); return getThis(); }  static ReferenceBuilder newBuilder(); ReferenceBuilder<T> id(String id); ReferenceBuilder<T> interfaceName(String interfaceName); ReferenceBuilder<T> interfaceClass(Class<?> interfaceClass); ReferenceBuilder<T> client(String client); ReferenceBuilder<T> url(String url); ReferenceBuilder<T> addMethods(List<MethodConfig> methods); ReferenceBuilder<T> addMethod(MethodConfig method); ReferenceBuilder<T> consumer(ConsumerConfig consumer); ReferenceBuilder<T> protocol(String protocol); ReferenceBuilder<T> services(String service, String... otherServices); ReferenceConfig<T> build();  }### Answer:
@Test void addMethod() { MethodConfig method = new MethodConfig(); ReferenceBuilder builder = new ReferenceBuilder(); builder.addMethod(method); Assertions.assertTrue(builder.build().getMethods().contains(method)); Assertions.assertEquals(1, builder.build().getMethods().size()); }