code: public void skip(K key) throws IOException {
      ArrayList<ComposableRecordReader<K,?>> tmp =
        new ArrayList<ComposableRecordReader<K,?>>();
      while (!q.isEmpty() && cmp.compare(q.peek().key(), key) <= 0) {
        tmp.add(q.poll());
      }
      for (ComposableRecordReader<K,?> rr : tmp) {
        rr.skip(key);
        if (rr.hasNext()) {
          q.add(rr);
        }
      }
    }
docs: Pass skip key to child RRs.