I'd like to propose a patch with following (minor) modifications on IntegerList class :
- Add a method to acquire an IntStream over an IntegerList values, to allow iteration over primitive values in an IntegerList,
- update AbstractList's modCount attribute when a modification happens over the list, which serves for multi-context modification.
You'll find a patch attached. It contains all modifications, which are located in IntegerList and related test class.
Hope it !