### Question:
MultiRabbitBootstrapConfiguration implements ImportBeanDefinitionRegistrar { @Override public void registerBeanDefinitions(final AnnotationMetadata importingClassMetadata, final BeanDefinitionRegistry registry) { registry.registerBeanDefinition(RabbitListenerConfigUtils.RABBIT_LISTENER_ANNOTATION_PROCESSOR_BEAN_NAME, new RootBeanDefinition(MultiRabbitListenerAnnotationBeanPostProcessor.class)); }  @Override void registerBeanDefinitions(final AnnotationMetadata importingClassMetadata,
                                        final BeanDefinitionRegistry registry);  }### Answer:
@Test public void shouldCreateMultiRabbitListenerAnnotationBeanPostProcessorBean() { configuration.registerBeanDefinitions(null, registry); verify(registry).registerBeanDefinition( RabbitListenerConfigUtils.RABBIT_LISTENER_ANNOTATION_PROCESSOR_BEAN_NAME, new RootBeanDefinition(MultiRabbitListenerAnnotationBeanPostProcessor.class)); }