}

  @Override
  Iterator<Entry<E>> entryIterator() {
    // AbstractIterator makes this fairly clean, but it doesn't support remove(). To support
    // remove(), we create an AbstractIterator, and then use ForwardingIterator to delegate to it.
    Iterator<Entry<E>> readOnlyIterator =
        new AbstractIterator<Entry<E>>() {
          private final Iterator<Map.Entry<E, AtomicInteger>> mapEntries =

              entriesByLowerBound
                  .headMap(subRange.upperBound, false)
                  .descendingMap()
                  .values()
                  .iterator();
          return new AbstractIterator<Entry<Range<K>, V>>() {

            @Override
            @CheckForNull
            protected Entry<Range<K>, V> computeNext() {
              if (backingItr.hasNext()) {

              entriesByLowerBound
                  .headMap(subRange.upperBound, false)
                  .descendingMap()
                  .values()
                  .iterator();
          return new AbstractIterator<Entry<Range<K>, V>>() {

            @Override
            @CheckForNull
            protected Entry<Range<K>, V> computeNext() {
              if (backingItr.hasNext()) {

        }
        result = size = Ints.saturatedCast(total);
      }
      return result.intValue();
    }

    @Override
    public UnmodifiableIterator<C> iterator() {
      return new AbstractIterator<C>() {
        final Iterator<Range<C>> rangeItr = ranges.iterator();
        Iterator<C> elemItr = emptyIterator();

        @Override
        @CheckForNull
        protected C computeNext() {

    PostOrderNode(T root, Iterator<T> childIterator) {
      this.root = checkNotNull(root);
      this.childIterator = checkNotNull(childIterator);
    }
  }

  private final class PostOrderIterator extends AbstractIterator<T> {
    private final ArrayDeque<PostOrderNode<T>> stack;

    PostOrderIterator(T root) {
      this.stack = new ArrayDeque<>();
      stack.addLast(expand(root));
    }

    @Override

        @Override
        Map<K, Collection<V>> map() {
          return AsMap.this;
        }

        @Override
        public Iterator<Entry<K, Collection<V>>> iterator() {
          return new AbstractIterator<Entry<K, Collection<V>>>() {
            final Iterator<Entry<K, Collection<V>>> backingIterator =
                unfiltered.asMap().entrySet().iterator();

            @Override
            @CheckForNull

        @Override
        Map<K, Collection<V>> map() {
          return AsMap.this;
        }

        @Override
        public Iterator<Entry<K, Collection<V>>> iterator() {
          return new AbstractIterator<Entry<K, Collection<V>>>() {
            final Iterator<Entry<K, Collection<V>>> backingIterator =
                unfiltered.asMap().entrySet().iterator();

            @Override
            @CheckForNull

import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Ascii;
import com.google.common.base.Optional;
import com.google.common.base.Splitter;
import com.google.common.collect.AbstractIterator;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.MustBeClosed;

    Iterator<C> merged =
        mergeSorted(
            transform(backingMap.values(), (Map<C, V> input) -> input.keySet().iterator()),
            comparator);

    return new AbstractIterator<C>() {
      @CheckForNull C lastValue;

      @Override
      @CheckForNull
      protected C computeNext() {
        while (merged.hasNext()) {
          C next = merged.next();

      final Iterable<? extends Optional<? extends T>> optionals) {
    checkNotNull(optionals);
    return new Iterable<T>() {
      @Override
      public Iterator<T> iterator() {
        return new AbstractIterator<T>() {
          private final Iterator<? extends Optional<? extends T>> iterator =
              checkNotNull(optionals.iterator());

          @Override
          @CheckForNull