private void addSignificances(List<Item> candidates, Ranking ranking) {
        for (Item  candidate : candidates) {
            TaggableItem t = (TaggableItem) candidate;
            if ( ! t.hasExplicitSignificance()) continue;
            String name = "vespa.term." + t.getUniqueID() + ".significance";
            ranking.getProperties().put(name, String.valueOf(t.getSignificance()));
        }
    }
Prepares this for binary serialization. For internal use.
container-search/src/main/java/com/yahoo/search/query/Model.java