@Override
    public void addLast(E elem) {
    	// inline version of add(elem):
    	doAdd(-1, elem);
    }
Helper method for adding multiple elements to the list.
This default implementation calls doAdd() for adding each element.

@param index index where element should be added
             (-1 is valid for adding at the end)
@return      true if elements have been added, false otherwise
jphp-runtime/src/php/runtime/memory/support/IList.java