public int getHitCount() {
        return hits.size();
    }
Returns the number of hit objects available in the top level group of this result.
Note that this number is allowed to be higher than the requested number
of hits, because a searcher is allowed to add <i>meta</i> hits as well
as the requested number of concrete hits.
container-search/src/main/java/com/yahoo/search/Result.java