public int getConcreteSize() {
        if (subgroupCount<1) return concreteHitCount;
        int recursiveConcreteCount=concreteHitCount;
        for (Hit hit : hits) {
            if (hit instanceof HitGroup)
                recursiveConcreteCount+=((HitGroup)hit).getConcreteSize();
        }
        return recursiveConcreteCount;
    }
<p>Returns the number of concrete hits contained in this group
and all subgroups. This should equal the
requested hits count if the query has that many matches.</p>
container-search/src/main/java/com/yahoo/search/result/HitGroup.java