@Override
        public boolean hasNext() {
            nextCalled = false;
            if (currentIterator.hasNext()) {
                return true;
            }
            if (annotationLists.isEmpty()) {
                return false;
            }
            currentIterator = annotationLists.remove(0).iterator();
            return hasNext();
        }
TODO: Should this be removed?

@author Einar M R Rosenvinge
document/src/main/java/com/yahoo/document/annotation/SpanNode2AnnotationContainer.java