}
    };

    abstract <R extends Comparable<R>, C extends Comparable<C>, V> Table<R, C, V> create(
        Table<R, C, V> contents);
  }

  public enum InternerImpl implements InternerImplEnum {
    WeakInternerImpl {
      @Override
      public <E> Interner<E> create(Collection<E> contents) {
        Interner<E> interner = Interners.newWeakInterner();