CompositeComponentDefinition compDefinition = new CompositeComponentDefinition(element.getTagName(), source);
parserContext.pushContainingComponent(compDefinition);
// Nest the concrete post-processor bean in the surrounding component.
BeanDefinitionRegistry registry = parserContext.getRegistry();
if (registry.containsBeanDefinition(ASYNC_ANNOTATION_PROCESSOR_BEAN_NAME)) {
parserContext.getReaderContext().error(
"Only one AsyncAnnotationBeanPostProcessor may exist within the context.", source);
}
else {
BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(