public boolean hasNext() {
      return keyIterator.hasNext() || valueIterator.hasNext();
    }

    @Override
    @ParametricNullness
    public T next() {
      if (!valueIterator.hasNext()) {
        Entry<K, Collection<V>> mapEntry = keyIterator.next();
        key = mapEntry.getKey();
        collection = mapEntry.getValue();
        valueIterator = collection.iterator();
      }
      /*

    Collection<String> values = map.values();
    values.remove("4");
    assertFalse(underlying.containsKey("d"));

    Iterator<String> valueIterator = values.iterator();
    valueIterator.next();
    valueIterator.remove();
    assertFalse(underlying.containsKey("e"));

    Set<Entry<String, String>> entries = map.entrySet();
    Entry<String, String> firstEntry = entries.iterator().next();

    }

    @Override
    public void remove() {
      iterator.remove();
    }
  }

  /** ValueIterator build on top of EntryIterator. */
  final class ValueIterator implements Iterator<V> {
    private EntryIterator iterator;

    ValueIterator() {
      iterator = new EntryIterator();
    }

    @Override
    public boolean hasNext() {
      return iterator.hasNext();

  FilteredMultimapValues(FilteredMultimap<K, V> multimap) {
    this.multimap = checkNotNull(multimap);
  }

  @Override
  public Iterator<V> iterator() {
    return Maps.valueIterator(multimap.entries().iterator());
  }

  @Override
  public boolean contains(@Nullable Object o) {
    return multimap.containsValue(o);
  }

  @Override
  public int size() {
    return multimap.size();

        return closed(set.first(), set.last());
      }
    }
    Iterator<C> valueIterator = values.iterator();
    C min = checkNotNull(valueIterator.next());
    C max = min;
    while (valueIterator.hasNext()) {
      C value = checkNotNull(valueIterator.next());
      min = Ordering.<C>natural().min(min, value);
      max = Ordering.<C>natural().max(max, value);
    }

    return (ImmutableCollection<V>) super.values();
  }

  @Override
  ImmutableCollection<V> createValues() {
    return new Values<>(this);
  }

  @Override
  UnmodifiableIterator<V> valueIterator() {
    return new UnmodifiableIterator<V>() {
      final Iterator<? extends ImmutableCollection<V>> valueCollectionItr = map.values().iterator();
      Iterator<V> valueItr = emptyIterator();

      @Override

    return (ImmutableCollection<V>) super.values();
  }

  @Override
  ImmutableCollection<V> createValues() {
    return new Values<>(this);
  }

  @Override
  UnmodifiableIterator<V> valueIterator() {
    return new UnmodifiableIterator<V>() {
      final Iterator<? extends ImmutableCollection<V>> valueCollectionItr = map.values().iterator();
      Iterator<V> valueItr = emptyIterator();

      @Override

    @Override
    protected Set<V> delegate() {
      return valuesDelegate;
    }

    @Override
    public Iterator<V> iterator() {
      return Maps.valueIterator(entrySet().iterator());
    }

    @Override
    public @Nullable Object[] toArray() {
      return standardToArray();
    }

    @Override

      @ParametricNullness
      K transform(Entry<K, V> entry) {
        return entry.getKey();
      }
    };
  }

  static <K extends @Nullable Object, V extends @Nullable Object> Iterator<V> valueIterator(
      Iterator<Entry<K, V>> entryIterator) {
    return new TransformedIterator<Entry<K, V>, V>(entryIterator) {
      @Override
      @ParametricNullness
      V transform(Entry<K, V> entry) {

      @ParametricNullness
      K transform(Entry<K, V> entry) {
        return entry.getKey();
      }
    };
  }

  static <K extends @Nullable Object, V extends @Nullable Object> Iterator<V> valueIterator(
      Iterator<Entry<K, V>> entryIterator) {
    return new TransformedIterator<Entry<K, V>, V>(entryIterator) {
      @Override
      @ParametricNullness
      V transform(Entry<K, V> entry) {