set.addAll(set1);
        set.addAll(set2);
        return set;
      }

      @Override
      @SuppressWarnings({"nullness", "unchecked"}) // see supertype
      public ImmutableSet<@NonNull E> immutableCopy() {
        ImmutableSet.Builder<@NonNull E> builder =
            new ImmutableSet.Builder<@NonNull E>()
                .addAll((Iterable<@NonNull E>) set1)

     * and will be merged, but overlapping ranges will cause an exception when {@link #build()} is
     * called.
     */
    @CanIgnoreReturnValue
    public Builder<C> addAll(RangeSet<C> ranges) {
      return addAll(ranges.asRanges());
    }

    /**
     * Add all of the specified ranges to this builder. Adjacent ranges are permitted and will be

            }

            Collection<String> versions =
                    new LinkedHashSet<>(recessive.getVersioning().getVersions());
            versions.addAll(original.getVersions());
            versioning.versions(new ArrayList<>(versions));
        }

        metadata = metadata.withVersioning(versioning.build());

        // just carry-on as-is

                    artifacts = directArtifacts;
                } else {
                    List<Artifact> allArtifacts = new ArrayList<>();
                    allArtifacts.addAll(artifacts);
                    allArtifacts.addAll(directArtifacts);

                    Map<String, Artifact> mergedArtifacts = new LinkedHashMap<>();
                    for (Artifact artifact : allArtifacts) {

     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> addAll(Iterator<? extends E> elements) {
      super.addAll(elements);
      return this;
    }

    @CanIgnoreReturnValue
    Builder<E> combine(Builder<E> other) {
      addAll(other.contents, other.size);
      return this;
    }

    /**

     * @return this {@code Builder} object
     * @throws NullPointerException if {@code elements} contains a null element
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> addAll(Iterable<? extends E> elements) {
      super.addAll(elements);
      return this;
    }

    /**
     * Adds each element of {@code elements} to the {@code ImmutableSortedSet}, ignoring duplicate

     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> addAll(Iterable<? extends E> elements) {
      checkNotNull(elements);
      if (hashTable != null) {
        for (E e : elements) {
          add(e);
        }
      } else {
        super.addAll(elements);
      }
      return this;
    }

    /**

     * @throws NullPointerException if {@code elements} is null or contains a null element
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> addAll(Iterator<? extends E> elements) {
      super.addAll(elements);
      return this;
    }

    /**
     * If the specified collection is backed by an ObjectCountHashMap, it will be much more

      E e1, E e2, E e3, E e4, E e5, E e6, E... remaining) {
    int size = remaining.length + 6;
    List<E> all = Lists.newArrayListWithCapacity(size);
    Collections.addAll(all, e1, e2, e3, e4, e5, e6);
    Collections.addAll(all, remaining);
    return copyOf(Ordering.natural(), all);
  }

  /**
   * Returns an immutable sorted multiset containing the given elements sorted by their natural
   * ordering.

    }

    @Override
    public int add(@ParametricNullness E element, int occurrences) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean addAll(Collection<? extends E> elementsToAdd) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean remove(@CheckForNull Object element) {