public void test_setAdditionalQuery() {
        queryHelper.setAdditionalQuery("additional query");
        assertEquals("additional query", queryHelper.getAdditionalQuery());
    }

    public void test_setHighlightPrefix() {
        queryHelper.setHighlightPrefix("highlight_");
        assertEquals("highlight_", queryHelper.getHighlightPrefix());
    }

    public void test_getHighlightPrefix() {