int num = RANDOM.nextInt(10);
        for (int i = 0; i < num; i++) {
          list.add(counter.getAndIncrement());
        }
        builder.addAll(list);
      }
    },
    ADD_ITERABLE {
      @Override
      void doIt(ImmutableIntArray.Builder builder, AtomicInteger counter) {
        List<Integer> list = new ArrayList<>();
        int num = RANDOM.nextInt(10);

        int num = RANDOM.nextInt(10);
        for (int i = 0; i < num; i++) {
          list.add(counter.getAndIncrement());
        }
        builder.addAll(list);
      }
    },
    ADD_ITERABLE {
      @Override
      void doIt(ImmutableIntArray.Builder builder, AtomicInteger counter) {
        List<Integer> list = new ArrayList<>();
        int num = RANDOM.nextInt(10);