}

  /**
   * Returns {@code element} cast to {@code E}, if it actually is a nonnull E. Otherwise, throws
   * either a NullPointerException or a ClassCastException as appropriate.
   */
  private void checkIsE(Object element) {
    checkNotNull(element);
    if (!isActuallyE(element)) {
      throw new ClassCastException("Expected an " + type + " but got " + element);
    }
  }

  @Override

    }

    /**
     * {@link Element}を文字列に変換します。
     *
     * @param element
     *            要素。{@literal null}であってはいけません
     * @return 変換された文字列
     */
    public static String toString(final Element element) {
        assertArgumentNotNull("element", element);

        final StringBuilder buf = new StringBuilder(1000);
        appendElement(element, buf);
        return new String(buf);
    }

    if (element instanceof Entry) {
      Entry<?, ?> entry = (Entry<?, ?>) element;
      element = mapEntry(entry.getKey(), entry.getValue());
    }
    assertTrue(collection.contains(element)); // sanity check
    iterator.remove();
    assertFalse(collection.contains(element));
    assertEquals(originalSize - 1, collection.size());
  }

                for (Plugin element : tgt) {
                    Object key = getPluginKey().apply(element);
                    Plugin existing = master.get(key);
                    if (existing != null) {
                        element = mergePlugin(element, existing, sourceDominant, context);

                        master.put(key, element);

                        if (!pending.isEmpty()) {

    }

    /**
     * Adds {@code element} to the {@code ImmutableSortedMultiset}.
     *
     * @param element the element to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code element} is null
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> add(E element) {
      return addCopies(element, 1);
    }

    /**

    assertEquals("Should be able to peek() at first element", "A", peekingIterator.peek());
    assertEquals(
        "Should be able to peek() first element multiple times", "A", peekingIterator.peek());
    assertEquals(
        "next() should still return first element after peeking", "A", peekingIterator.next());

    assertEquals("Should be able to peek() at middle element", "B", peekingIterator.peek());
    assertEquals(

  /** Returns {@code true} if {@code iterator} contains {@code element}. */
  public static boolean contains(Iterator<?> iterator, @CheckForNull Object element) {
    if (element == null) {
      while (iterator.hasNext()) {
        if (iterator.next() == null) {
          return true;
        }
      }
    } else {
      while (iterator.hasNext()) {
        if (element.equals(iterator.next())) {
          return true;
        }

    /**
     * Returns true if this set contains the specified element.
     *
     * @param o
     *            element whose presence in this set is to be tested.
     * @return true if this set contains the specified element.
     */
    @Override
    public boolean contains(final Object o) {
        return map.containsKey(o);
    }

    /**
     * Adds the specified element to this set if it is not already present.
     *

    MinMaxPriorityQueue<Element> queue = MinMaxPriorityQueue.create();
    int range = Element.values().length;
    for (int iter = 0; iter < reduceIterationsIfGwt(1000); iter++) {
      for (int i = 0; i < 100; i++) {
        Element element = Element.values()[random.nextInt(range)];
        elements.add(element);
        queue.add(element);
      }

  // Query Operations

  /**
   * Returns the number of occurrences of {@code element} in this multiset.
   *
   * @param element the element to look for
   * @return the nonnegative number of occurrences of the element
   */
  @Override
  public int count(@CheckForNull Object element) {
    AtomicInteger existingCounter = Maps.safeGet(countMap, element);
    return (existingCounter == null) ? 0 : existingCounter.get();
  }