private static PhraseItem convertAndToPhrase(AndItem andItem) {
        PhraseItem result = new PhraseItem();
        Iterator<Item> subItems = andItem.getItemIterator();
        while(subItems.hasNext()) {
            Item curr = (subItems.next());
            if (curr instanceof IntItem) {
                WordItem numItem = new WordItem(((IntItem)curr).stringValue());
                result.addItem(numItem);
            } else {
                result.addItem(curr);
            }
        }
        return result;
    }
Convert AndItem to PhraseItem<br>

e.g. (AND a b) to "a b"
@param andItem query tree to be converted
@return converted PhraseItem
container-search/src/main/java/com/yahoo/search/query/rewrite/RewriterFeatures.java