public static PhraseMatcher getNullMatcher() {

        return new PhraseMatcher() {

            @Override
            public List<Phrase> matchPhrases(Item item) {
                    return null;
                }

        };

    }
Returns a phrase matcher which (quickly) never matches anything
container-search/src/main/java/com/yahoo/prelude/querytransform/PhraseMatcher.java