private static boolean equalWeakAndSettings(WeakAndItem a, WeakAndItem b) {
        if ( ! a.getIndexName().equals(b.getIndexName())) return false;
        if (a.getN() != b.getN()) return false;
        return true;
    }
Collapse the next item of this iterator into the given parent, if appropriate
container-search/src/main/java/com/yahoo/prelude/query/QueryCanonicalizer.java