private AsyncEventQueueCreation peekAsyncEventQueueContext(String dependentElement) {
    Object a = stack.peek();
    if (!(a instanceof AsyncEventQueueCreation)) {
      throw new CacheXmlException(
          String.format("A %s must be defined in the context of async-event-queue.",
              dependentElement));
    }
    return (AsyncEventQueueCreation) a;
  }
When a <code>cache-listener</code> element is finished, the {@link Parameter}s and class names
are popped off the stack. The cache listener is instantiated and initialized with the
parameters, if appropriate.
geode-core/src/main/java/org/apache/geode/internal/cache/xmlcache/CacheXmlParser.java