@J2ktIncompatible // serialization
  Object writeReplace() {
    return new SerializedForm<E>(comparator, toArray());
  }

  /**
   * Not supported. Use {@link #toImmutableSortedSet} instead. This method exists only to hide
   * {@link ImmutableSet#toImmutableSet} from consumers of {@code ImmutableSortedSet}.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Use {@link ImmutableSortedSet#toImmutableSortedSet}.

  private static final long serialVersionUID = 0;

  /**
   * Not supported. Use {@link #toImmutableSortedMap}, which offers better type-safety, instead.
   * This method exists only to hide {@link ImmutableMap#toImmutableMap} from consumers of {@code
   * ImmutableSortedMap}.
   *
   * @throws UnsupportedOperationException always

    throw new InvalidObjectException("Use SerializedForm");
  }

  /**
   * Not supported. Use {@link #toImmutableBiMap} instead. This method exists only to hide {@link
   * ImmutableMap#toImmutableMap(Function, Function)} from consumers of {@code ImmutableBiMap}.
   *
   * @throws UnsupportedOperationException always

      }
      ImmutableSet<Object> valueSet = valuesBuilder.build();
      if (valueSet.size() != valueCount) {
        throw new InvalidObjectException("Duplicate key-value pairs exist for key " + key);
      }
      builder.put(key, valueSet);
      tmpSize += valueCount;
    }

    ImmutableMap<Object, ImmutableSet<Object>> tmpMap;
    try {
      tmpMap = builder.buildOrThrow();

    throw new InvalidObjectException("Use SerializedForm");
  }

  /**
   * Not supported. Use {@link #toImmutableSortedMultiset} instead. This method exists only to hide
   * {@link ImmutableMultiset#toImmutableMultiset} from consumers of {@code
   * ImmutableSortedMultiset}.
   *
   * @throws UnsupportedOperationException always

   * iterator containing two inner lists of three elements each, all in the original order.
   *
   * <p>The returned lists implement {@link java.util.RandomAccess}.
   *
   * @param iterator the iterator to return a partitioned view of
   * @param size the desired size of each partition
   * @return an iterator of immutable lists containing the elements of {@code iterator} divided into