private String enc(String s) {
        try {
            return URLEncoder.encode(s, "utf-8");
        }
        catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e);
        }
    }
Check CollapsePhraseSearcher works and only is triggered when it
should.

@author Steinar Knutsen
container-search/src/test/java/com/yahoo/prelude/querytransform/test/CollapsePhraseSearcherTestCase.java