### Question:
ExtendedBeanDefinitionRegistryImpl implements ExtendedBeanDefinitionRegistry { @Override public void registerBeanDefinition(String beanName, BeanDefinition beanDefinition) { registry.registerBeanDefinition(beanName, beanDefinition); } ExtendedBeanDefinitionRegistryImpl(BeanDefinitionRegistry registry); @Override Set<BeanDefinitionMetadata> getBeanDefinitionsForClass(Class<?> clazz); @Override void registerBeanDefinition(String beanName, BeanDefinition beanDefinition);  }### Answer:
@Test void register_bean_definition_delegates() { BeanDefinitionRegistry delegate = mock(BeanDefinitionRegistry.class); ExtendedBeanDefinitionRegistry extendedRegistry = new ExtendedBeanDefinitionRegistryImpl(delegate); extendedRegistry.registerBeanDefinition("test", null); verify(delegate, times(1)).registerBeanDefinition(any(), any()); }