return (SortedMap<K, V>) unfiltered;
    }

    @Override
    public SortedSet<K> keySet() {
      return (SortedSet<K>) super.keySet();
    }

    @Override
    SortedSet<K> createKeySet() {
      return new SortedKeySet();
    }

    @WeakOuter
    final class SortedKeySet extends KeySet implements SortedSet<K> {
      @Override
      public @Nullable Comparator<? super K> comparator() {

      return (SortedMap<K, V>) unfiltered;
    }

    @Override
    public SortedSet<K> keySet() {
      return (SortedSet<K>) super.keySet();
    }

    @Override
    SortedSet<K> createKeySet() {
      return new SortedKeySet();
    }

    @WeakOuter
    final class SortedKeySet extends KeySet implements SortedSet<K> {
      @Override
      public @Nullable Comparator<? super K> comparator() {

     * to know they are SortedSets and probably would not call this method.
     */
    if (iterable instanceof SortedSet) {
      SortedSet<E> sortedSet = (SortedSet<E>) iterable;
      return Optional.of(sortedSet.last());
    }

    while (true) {
      E current = iterator.next();
      if (!iterator.hasNext()) {
        return Optional.of(current);
      }

     * to know they are SortedSets and probably would not call this method.
     */
    if (iterable instanceof SortedSet) {
      SortedSet<E> sortedSet = (SortedSet<E>) iterable;
      return Optional.of(sortedSet.last());
    }

    while (true) {
      E current = iterator.next();
      if (!iterator.hasNext()) {
        return Optional.of(current);
      }

import java.util.Comparator;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.SortedSet;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**