@Override
    public FieldPart previous() {
        int i = index;
        while (i > 0) {
            i--;
            if (fieldList.get(i).isToken()) {
                index = i;
                prevReturned = i;
                return fieldList.get(i);
            }
        }
        throw new NoSuchElementException("Trying to go before first token available.");
    }
A specialized list iterator to manipulate tokens in HitField objects.

@author Steinar Knutsen
container-search/src/main/java/com/yahoo/prelude/hitfield/TokenFieldIterator.java