*
   * <p><b>Warning:</b> If an existing entry with this value is removed, the key for that entry is
   * discarded and not returned.
   *
   * @param key the key with which the specified value is to be associated
   * @param value the value to be associated with the specified key
   * @return the value that was previously associated with the key, or {@code null} if there was no

    @SuppressWarnings("unchecked")
    Entry<String, String>[] array = (Entry<String, String>[]) new Entry<?, ?>[entries.length];
    int i = 0;
    for (Object o : entries) {
      @SuppressWarnings("unchecked")
      Entry<String, String> e = (Entry<String, String>) o;
      array[i++] = e;
    }
    return create(array);
  }

  protected abstract ListMultimap<String, String> create(Entry<String, String>[] entries);

  @Override

    @SuppressWarnings("unchecked")
    Entry<String, String>[] array = (Entry<String, String>[]) new Entry<?, ?>[entries.length];
    int i = 0;
    for (Object o : entries) {
      @SuppressWarnings("unchecked")
      Entry<String, String> e = (Entry<String, String>) o;
      array[i++] = e;
    }
    return create(array);
  }

  protected abstract SetMultimap<String, String> create(Entry<String, String>[] entries);

  @Override

        protected Entry next;

        /** 前のエントリ */
        protected Entry previous;

        Entry(final E element, final Entry next, final Entry previous) {
            this.element = element;
            this.next = next;
            this.previous = previous;
        }

        /**
         * 要素を返します。
         *
         * @return 要素
         */
        public E getElement() {

    Entry<K, V> entry = lastEntry();
    if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  @CheckForNull
  public Entry<K, V> lowerEntry(@ParametricNullness K key) {
    return headMap(key, false).lastEntry();
  }

  @Override
  @CheckForNull
  public Entry<K, V> floorEntry(@ParametricNullness K key) {
    return headMap(key, true).lastEntry();

  @CollectionSize.Require(absent = ZERO)
  public void testSetValue_valueAbsent() {
    for (Entry<K, V> entry : getMap().entrySet()) {
      if (entry.getKey().equals(k0())) {
        assertEquals("entry.setValue() should return the old value", v0(), entry.setValue(v3()));
      }
    }
    expectReplacement(entry(k0(), v3()));
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(SEVERAL)

    for (Entry<? extends K, ? extends V> entry : map.entrySet()) {
      put(entry.getKey(), entry.getValue());
    }
  }

  @Override
  public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
    this.delegate.replaceAll(function);
    inverse.delegate.clear();
    Entry<K, V> broken = null;
    Iterator<Entry<K, V>> itr = this.delegate.entrySet().iterator();

   */
  @CheckForNull
  protected Entry<E> standardPollFirstEntry() {
    Iterator<Entry<E>> entryIterator = entrySet().iterator();
    if (!entryIterator.hasNext()) {
      return null;
    }
    Entry<E> entry = entryIterator.next();
    entry = Multisets.immutableEntry(entry.getElement(), entry.getCount());
    entryIterator.remove();
    return entry;
  }

  @Override
  @CheckForNull

                  @Override
                  protected SortedMap<String, String> create(Entry<String, String>[] entries) {
                    NavigableMap<String, String> map = new SafeTreeMap<>(Ordering.natural());
                    for (Entry<String, String> entry : entries) {
                      map.put(entry.getKey(), entry.getValue());
                    }
                    return map;
                  }

                  @Override
                  protected SortedMap<String, String> create(Entry<String, String>[] entries) {
                    NavigableMap<String, String> map = new SafeTreeMap<>(Ordering.natural());
                    for (Entry<String, String> entry : entries) {
                      map.put(entry.getKey(), entry.getValue());
                    }
                    return map;
                  }