private void setWeight(Item replacement, int weight) {
        if (replacement instanceof AndSegmentItem) {
            for (Iterator<Item> i = ((AndSegmentItem) replacement).getItemIterator();
                    i.hasNext();) {
                i.next().setWeight(weight);
            }
        } else {
            replacement.setWeight(weight);
        }
    }
Replaces query terms with their stems

@author Mathias Lidal
@author bratseth
@author Steinar Knutsen
container-search/src/main/java/com/yahoo/prelude/querytransform/StemmingSearcher.java