return OldConcurrentHashMultiset.create();
      }
    },
    SYNCHRONIZED_MULTISET() {
      @Override
      Multiset<Integer> get() {
        return Synchronized.multiset(HashMultiset.<Integer>create(), null);
      }
    },
    ;

    abstract Multiset<Integer> get();
  }

  /**
   * Duplication of the old version of ConcurrentHashMultiset (with some unused stuff removed, like

        return OldConcurrentHashMultiset.create();
      }
    },
    SYNCHRONIZED_MULTISET() {
      @Override
      Multiset<Integer> get() {
        return Synchronized.multiset(HashMultiset.<Integer>create(), null);
      }
    },
    ;

    abstract Multiset<Integer> get();
  }

  /**
   * Duplication of the old version of ConcurrentHashMultiset (with some unused stuff removed, like