public @Nullable Entry<K, V> pollLastEntry() {
    return Iterators.pollNext(descendingEntryIterator());
  }

  @Override
  @ParametricNullness
  public K firstKey() {
    Entry<K, V> entry = firstEntry();
    if (entry == null) {
      throw new NoSuchElementException();
    } else {
      return entry.getKey();
    }
  }

  @Override
  @ParametricNullness
  public K lastKey() {

   */
  protected @Nullable 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

  }

  /** Makes an entry usable internally by a new ImmutableMap. */
  static <K, V> ImmutableMapEntry<K, V> makeImmutable(Entry<K, V> entry) {
    return makeImmutable(entry, entry.getKey(), entry.getValue());
  }

  private RegularImmutableMap(
      Entry<K, V>[] entries, @Nullable ImmutableMapEntry<K, V> @Nullable [] table, int mask) {
    this.entries = entries;

      for (ValueEntry<K, V> entry = hashTable[bucket];
          entry != null;
          prev = entry, entry = entry.nextInValueBucket) {
        if (entry.matchesValue(o, smearedHash)) {
          if (prev == null) {
            // first entry in the bucket
            hashTable[bucket] = entry.nextInValueBucket;
          } else {
            prev.nextInValueBucket = entry.nextInValueBucket;
          }

    @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 Map<String, String> create(Entry<String, String>[] entries);

  @Override

      for (ValueEntry<K, V> entry = hashTable[bucket];
          entry != null;
          prev = entry, entry = entry.nextInValueBucket) {
        if (entry.matchesValue(o, smearedHash)) {
          if (prev == null) {
            // first entry in the bucket
            hashTable[bucket] = entry.nextInValueBucket;
          } else {
            prev.nextInValueBucket = entry.nextInValueBucket;
          }

    @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 BiMap<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 BiMap<String, String> create(Entry<String, String>[] entries);

  @Override

  }

  @SuppressWarnings("unchecked")
  ForwardingImmutableMap(boolean throwIfDuplicateKeys, Entry<? extends K, ? extends V>... entries) {
    Map<K, V> delegate = Maps.newLinkedHashMap();
    for (Entry<? extends K, ? extends V> entry : entries) {
      K key = checkNotNull(entry.getKey());
      V previous = delegate.put(key, checkNotNull(entry.getValue()));
      if (throwIfDuplicateKeys && previous != null) {

     *
     * @param first the first entry of the table
     * @param entry the entry being removed from the table
     * @return the new first entry for the table
     */
    @GuardedBy("this")
    @Nullable E removeFromChain(E first, E entry) {
      int newCount = count;
      E newFirst = entry.getNext();
      for (E e = first; e != entry; e = e.getNext()) {
        E next = copyEntry(e, newFirst);