*
     * @param elements the elements to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code elements} is null or contains a null element
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> add(E... elements) {
      super.add(elements);
      return this;
    }

    /**

      return ImmutableSet.copyOf(elements);
    }
  }

  public static class DegeneratedImmutableSetGenerator extends TestStringSetGenerator {
    @SuppressWarnings("DistinctVarargsChecker") // deliberately testing deduplication
    @Override
    protected Set<String> create(String[] elements) {
      return ImmutableSet.of(elements[0], elements[0]);
    }
  }

    // We special-case for 0 or 1 elements, but going further is madness.
    if (!elements.hasNext()) {
      return of();
    }
    E first = elements.next();
    if (!elements.hasNext()) {
      return of(first);
    } else {
      return new ImmutableList.Builder<E>().add(first).addAll(elements).build();
    }
  }

  /**
   * Returns an immutable list containing the given elements, in order.

    public Builder<E> add(E... elements) {
      for (E element : elements) {
        add(element);
      }
      return this;
    }

    /**
     * Adds each element of {@code elements} to the {@code ImmutableCollection} being built.
     *
     * <p>Note that each builder class overrides this method in order to covariantly return its own
     * type.
     *
     * @param elements the elements to add

   * have been removed.
   *
   * <p><b>Warning:</b> Typical uses of the resulting iterator may produce an infinite loop. You
   * should use an explicit {@code break} or be certain that you will eventually remove all the
   * elements.
   *
   * <p>To cycle over the elements {@code n} times, use the following: {@code
   * Iterables.concat(Collections.nCopies(n, Arrays.asList(elements)))}
   *

  /**
   * Returns the expected number of distinct elements given the specified elements. The number of
   * distinct elements is only computed if {@code elements} is an instance of {@code Multiset};
   * otherwise the default value of 11 is returned.
   */
  static int inferDistinctElements(Iterable<?> elements) {
    if (elements instanceof Multiset) {
      return ((Multiset<?>) elements).elementSet().size();
    }

  /**
   * Inserts the specified element into this priority queue.
   *
   * @param e the element to add
   * @return {@code true} (as specified by {@link Queue#offer})
   * @throws ClassCastException if the specified element cannot be compared with elements currently
   *     in the priority queue according to the priority queue's ordering
   * @throws NullPointerException if the specified element is null
   */

   * have been removed.
   *
   * <p><b>Warning:</b> Typical uses of the resulting iterator may produce an infinite loop. You
   * should use an explicit {@code break} or be certain that you will eventually remove all the
   * elements.
   *
   * <p>To cycle over the elements {@code n} times, use the following: {@code
   * Iterables.concat(Collections.nCopies(n, Arrays.asList(elements)))}
   *

   * Creates a new {@code EnumMultiset} containing the specified elements.
   *
   * <p>This implementation is highly efficient when {@code elements} is itself a {@link Multiset}.
   *
   * @param elements the elements that the multiset should contain
   * @throws IllegalArgumentException if {@code elements} is empty
   */
  public static <E extends Enum<E>> EnumMultiset<E> create(Iterable<E> elements) {
    Iterator<E> iterator = elements.iterator();

    // We special-case for 0 or 1 elements, but going further is madness.
    if (!elements.hasNext()) {
      return of();
    }
    E first = elements.next();
    if (!elements.hasNext()) {
      return of(first);
    } else {
      return new ImmutableList.Builder<E>().add(first).addAll(elements).build();
    }
  }

  /**
   * Returns an immutable list containing the given elements, in order.