private void appendRemainingIfNeeded(List<LeanHit> merged, int needed, List<LeanHit> hits, int index) {
        while ((index < hits.size()) && (merged.size() < needed)) {
            merged.add(hits.get(index++));
        }
    }
Sends search queries to the contained {@link SearchInvoker} sub-invokers. If the search
query has an offset other than zero, it will be reset to zero and the expected hit amount
will be adjusted accordingly.
container-search/src/main/java/com/yahoo/search/dispatch/InterleavedSearchInvoker.java