return checkNotNull(ordering);
  }

  /**
   * Returns an ordering that compares objects according to the order in which they appear in the
   * given list. Only objects present in the list (according to {@link Object#equals}) may be
   * compared. This comparator imposes a "partial ordering" over the type {@code T}. Subsequent

    return checkNotNull(ordering);
  }

  /**
   * Returns an ordering that compares objects according to the order in which they appear in the
   * given list. Only objects present in the list (according to {@link Object#equals}) may be
   * compared. This comparator imposes a "partial ordering" over the type {@code T}. Subsequent

   * priority queue will be ordered according to the same ordering. Otherwise, this priority queue
   * will be ordered according to the {@linkplain Comparable natural ordering} of its elements.
   *
   * @param c the collection whose elements are to be placed into this priority queue
   * @throws ClassCastException if elements of the specified collection cannot be compared to one
   *     another according to the priority queue's ordering

   * keys and values are the result of applying the provided mapping functions to the input
   * elements. The generated map is sorted by the specified comparator.
   *
   * <p>If the mapped keys contain duplicates (according to the specified comparator), an {@code
   * IllegalArgumentException} is thrown when the collection operation is performed. (This differs
   * from the {@code Collector} returned by {@link Collectors#toMap(Function, Function)}, which

  // The mask for the significand, according to the {@link
  // Double#doubleToRawLongBits(double)} spec.
  static final long SIGNIFICAND_MASK = 0x000fffffffffffffL;

  // The mask for the exponent, according to the {@link
  // Double#doubleToRawLongBits(double)} spec.
  static final long EXPONENT_MASK = 0x7ff0000000000000L;

  // The mask for the sign, according to the {@link
  // Double#doubleToRawLongBits(double)} spec.

        // Insert elements that should be ordered according to ELEMENT_ORDER
        DomUtils.insertContentElement(root, "description", "Test description");
        DomUtils.insertContentElement(root, "name", "Test Project");
        DomUtils.insertNewElement("properties", root);

        String xmlOutput = DomUtils.toXml(doc);

        // Verify that elements appear in the correct order according to ELEMENT_ORDER

   * keys and values are the result of applying the provided mapping functions to the input
   * elements. The generated map is sorted by the specified comparator.
   *
   * <p>If the mapped keys contain duplicates (according to the specified comparator), an {@code
   * IllegalArgumentException} is thrown when the collection operation is performed. (This differs
   * from the {@code Collector} returned by {@link Collectors#toMap(Function, Function)}, which

    return new LexicographicalOrdering<S>(checkNotNull(comparator));
  }

  /**
   * Returns {@code true} if each element in {@code iterable} after the first is greater than or
   * equal to the element that preceded it, according to the specified comparator. Note that this is
   * always true when the iterable has fewer than two elements.
   */
  public static <T extends @Nullable Object> boolean isInOrder(

    return new LexicographicalOrdering<S>(checkNotNull(comparator));
  }

  /**
   * Returns {@code true} if each element in {@code iterable} after the first is greater than or
   * equal to the element that preceded it, according to the specified comparator. Note that this is
   * always true when the iterable has fewer than two elements.
   */
  public static <T extends @Nullable Object> boolean isInOrder(

 * implicit target of the methods {@link #peek()}, {@link #poll()} and {@link #remove()} -- is
 * defined as the <i>least</i> element in the queue according to the queue's comparator. But unlike
 * a regular priority queue, the methods {@link #peekLast}, {@link #pollLast} and {@link
 * #removeLast} are also provided, to act on the <i>greatest</i> element in the queue instead.
 *