Collections.addAll(multiset, elements);
        return multiset;
      }

      @Override
      public List<String> order(List<String> insertionOrder) {
        return Ordering.natural().sortedCopy(insertionOrder);
      }
    };
  }

  private static final String KEY = "puppies";

  ConcurrentMap<String, AtomicInteger> backingMap;
  ConcurrentHashMultiset<String> multiset;