public E next() {
        lockChain();
        updateCurrentIterator();
        lastUsedIterator = currentIterator;

        return currentIterator.next();
    }
Returns the next Object of the current Iterator

@return Object from the current Iterator
@throws java.util.NoSuchElementException
         if all the Iterators are exhausted
jphp-runtime/src/php/runtime/common/collections/iterators/IteratorChain.java