Hash {
      @Override
      Map<Element, Element> create(Collection<Element> keys) {
        Map<Element, Element> map = Maps.newHashMap();
        for (Element element : keys) {
          map.put(element, element);
        }
        return map;
      }
    },
    LinkedHM {
      @Override
      Map<Element, Element> create(Collection<Element> keys) {
        Map<Element, Element> map = Maps.newLinkedHashMap();

        }

        Document document = parent.getOwnerDocument();

        Element section = document.createElement("section");
        parent.appendChild(section);

        Element title = document.createElement("title");
        section.appendChild(title);
        title.appendChild(document.createTextNode("Script blocks added by the "));
        Element literal = document.createElement("literal");
        title.appendChild(literal);

        }

        Document document = parent.getOwnerDocument();

        Element section = document.createElement("section");
        parent.appendChild(section);

        Element title = document.createElement("title");
        section.appendChild(title);
        title.appendChild(document.createTextNode("Properties added by the "));
        Element literal = document.createElement("literal");
        title.appendChild(literal);

  @Override
  public int count(@CheckForNull Object element) {
    return delegate().count(element);
  }

  @CanIgnoreReturnValue
  @Override
  public int add(@ParametricNullness E element, int occurrences) {
    return delegate().add(element, occurrences);
  }

  @CanIgnoreReturnValue
  @Override
  public int remove(@CheckForNull Object element, int occurrences) {
    return delegate().remove(element, occurrences);

    }

    @Override
    public @Nullable E peek() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.peek();
    }

    @Override
    public E element() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.element();
    }

    @Override
    public Iterator<E> iterator() {
      // We explicitly don't lock for iterator()
      assertFalse(Thread.holdsLock(mutex));

   * of their elements."
   *
   * </blockquote>
   */
  RESTRICTS_ELEMENTS,

  /**
   * Indicates that a collection has a well-defined ordering of its elements. The ordering may
   * depend on the element values, such as a {@link SortedSet}, or on the insertion ordering, such
   * as a {@link LinkedHashSet}. All list tests and sorted-collection tests automatically specify
   * this feature.
   */

   * ordering of the elements is used.
   */
  @Override
  Comparator<? super E> comparator();

  /**
   * Returns the entry of the first element in this multiset, or {@code null} if this multiset is
   * empty.
   */
  @CheckForNull
  Entry<E> firstEntry();

  /**
   * Returns the entry of the last element in this multiset, or {@code null} if this multiset is
   * empty.
   */

      }

      @Override
      public T set(int index, T element) {
        return data.set(index, element);
      }

      @Override
      public boolean add(T element) {
        return data.add(element);
      }

      @Override
      public void add(int index, T element) {
        data.add(index, element);
      }

      @Override
      public T remove(int index) {

     * 
     * @param delimiter
     * @param elements
     * @return elements separated by delimiter
     */
    public static String join ( CharSequence delimiter, CharSequence... elements ) {
        StringBuilder sb = new StringBuilder();
        for ( CharSequence element : elements ) {
            if ( sb.length() > 0 ) {
                if ( delimiter != null ) {

  private SetImpl impl;

  // the following must be set during setUp
  private Set<Element> setToTest;

  @BeforeExperiment
  void setUp() {
    CollectionBenchmarkSampleData sampleData =
        new CollectionBenchmarkSampleData(true, random, 0.8, size);
    setToTest = (Set<Element>) impl.create(sampleData.getValuesInSet());
  }

  @Benchmark
  int iteration(int reps) {
    int x = 0;