code: @SuppressWarnings("unchecked")
      public ManagedSet parseListeners(Element element, ParserContext parserContext) {
          ManagedSet listeners = new ManagedSet();
          NodeList childNodes = element.getChildNodes();
          for (int i = 0; i < childNodes.getLength(); i++) {
              Node child = childNodes.item(i);
              if (child.getNodeType() == Node.ELEMENT_NODE) {
                  Element childElement = (Element) child;
                  String localName = child.getLocalName();
                  if ("bean".equals(localName)) {
                      BeanDefinitionHolder holder = parserContext.getDelegate().parseBeanDefinitionElement(childElement);
                      parserContext.registerBeanComponent(new BeanComponentDefinition(holder));
                      listeners.add(new RuntimeBeanReference(holder.getBeanName()));
                  } else if ("ref".equals(localName)) {
                      String ref = childElement.getAttribute("bean");
                      listeners.add(new RuntimeBeanReference(ref));
                  }
              }
          }
          return listeners;
      }
docs: Parses out a set of configured esper statement listeners.
  
  @param element
  the esper listeners element
  @param parserContext
  the parser's current context
  @return a list of configured esper statement listeners