};
  }

  enum QueueImpl implements CollectionsImplEnum {
    MinMaxPriorityQueueImpl {
      @Override
      public <E extends Comparable<E>> Queue<E> create(Collection<E> contents) {
        return MinMaxPriorityQueue.create(contents);
      }
    };
  }

  enum TableImpl {
    HashBasedTableImpl {
      @Override
      <R extends Comparable<R>, C extends Comparable<C>, V> Table<R, C, V> create(