1. run the attached example
2. compare clicking "index" button and other 2 buttons (for, iterator)
- "index" doesn't always cause an exception
- for & iterator always throws ConcurrentModificationException
implement with a loop that failed fast is better to expose the root cause, so that application developers can fix their problem eariler.
- at at org.zkoss.bind.impl.LoadChildrenBindingImpl.load(LoadChildrenBindingImpl.java:121)