Iterator<ReferenceEntry<Object, Object>> i = readOrder.iterator();
      while (i.hasNext()) {
        ReferenceEntry<Object, Object> entry = i.next();
        if (random.nextBoolean()) {
          map.get(entry.getKey(), loader);
          reads.add(entry);
          i.remove();
          assertTrue(segment.recencyQueue.size() <= DRAIN_THRESHOLD);
        }
      }