Entry<K, V> entry = requireNonNull(entryArray[i]);
            Object key = entry.getKey();
            Object value = entry.getValue();
            checkEntryNotNull(key, value);
            keys[i] = key;
            values[i] = value;
          }
        } else {
          // Need to sort and check for nulls and dupes.

    }

    @Override
    public boolean containsValue(@CheckForNull Object value) {
      return map.containsValue(value);
    }

    @Override
    public boolean containsEntry(@CheckForNull Object key, @CheckForNull Object value) {
      return map.entrySet().contains(Maps.immutableEntry(key, value));
    }

    @Override
    public Set<V> get(@ParametricNullness final K key) {

  }

  /**
   * Returns an iterator containing only {@code value}.
   *
   * <p>The {@link Iterable} equivalent of this method is {@link Collections#singleton}.
   */
  public static <T extends @Nullable Object> UnmodifiableIterator<T> singletonIterator(
      @ParametricNullness T value) {
    if (value != null) {
      return new SingletonIterator<>(value);
    }