if (next == null) {
        throw new NoSuchElementException();
      }
      current = next;
      seenKeys.add(current.getKey());
      do { // skip ahead to next unseen key
        next = next.next;
      } while ((next != null) && !seenKeys.add(next.getKey()));
      return current.getKey();
    }

    @Override
    public void remove() {
      checkForConcurrentModification();

    boolean changed = false;
    while (entryIterator.hasNext()) {
      Entry<K, Collection<V>> entry = entryIterator.next();
      K key = entry.getKey();
      Collection<V> collection = filterCollection(entry.getValue(), new ValuePredicate(key));
      if (!collection.isEmpty()
          && predicate.apply(Maps.<K, Collection<V>>immutableEntry(key, collection))) {

      return new WrappedSortedSet(
          getKey(),
          getSortedSetDelegate().headSet(toElement),
          (getAncestor() == null) ? this : getAncestor());
    }

    @Override
    public SortedSet<V> subSet(@ParametricNullness V fromElement, @ParametricNullness V toElement) {
      refreshIfEmpty();
      return new WrappedSortedSet(
          getKey(),

  @MapFeature.Require(SUPPORTS_PUT)
  @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)

            result.setName(DfTypeUtil.toString(source.get("name")));
            result.setAttributes(source.entrySet()
                    .stream()
                    .filter(e -> !"name".equals(e.getKey()))
                    .map(e -> new Pair<>(e.getKey(), (String) e.getValue()))
                    .collect(Collectors.toMap(Pair::getFirst, Pair::getSecond)));
            return result;

    BiMap<K, V> bimap = (BiMap<K, V>) map;

    for (Entry<K, V> entry : map.entrySet()) {
      assertThat(entry.toString()).isEqualTo(entry.getKey() + "=" + entry.getValue());
      assertEquals(entry.getKey(), bimap.inverse().get(entry.getValue()));
    }

    assertThat(map.toString()).isEqualTo("{" + JOINER.join(map.entrySet()) + "}");

      rowBuilder.put(row.getKey(), ImmutableMap.copyOf(row.getValue()));
    }
    this.rowMap = rowBuilder.buildOrThrow();

    ImmutableMap.Builder<C, ImmutableMap<R, V>> columnBuilder =
        new ImmutableMap.Builder<>(columns.size());
    for (Entry<C, Map<R, V>> col : columns.entrySet()) {
      columnBuilder.put(col.getKey(), ImmutableMap.copyOf(col.getValue()));
    }

    public void remove() {
      checkState(lastReturned != null);
      LocalCache.this.remove(lastReturned.getKey());
      lastReturned = null;
    }
  }

  final class KeyIterator extends HashIterator<K> {

    @Override
    public K next() {
      return nextEntry().getKey();
    }
  }

  final class ValueIterator extends HashIterator<V> {

    @Override

      ImmutableBiMap.Builder<String, String> builder = ImmutableBiMap.builder();
      for (Entry<String, String> entry : entries) {
        checkNotNull(entry);
        builder.put(entry.getKey(), entry.getValue());
      }
      return builder.build();
    }
  }

  public static class ImmutableBiMapCopyOfGenerator extends TestStringBiMapGenerator {
    @Override

    public int compare(Entry<K, V> a, Entry<K, V> b) {
      return (keyComparator == null)
          ? ((Comparable) a.getKey()).compareTo(b.getKey())
          : keyComparator.compare(a.getKey(), b.getKey());
    }
  }

  public static <K extends @Nullable Object, V extends @Nullable Object>