NavigableSet<Integer> filtered = filter(createUnfiltered(contents), EVEN);
        NavigableSet<Integer> unfiltered = createUnfiltered(filtered);

        assertEquals(unfiltered.pollLast(), filtered.pollLast());
        assertEquals(unfiltered, filtered);
      }
    }

    public void testNavigation() {
      for (List<Integer> contents : SAMPLE_INPUTS) {

  @WeakOuter
  final class WrappedNavigableSet extends WrappedSortedSet implements NavigableSet<V> {
    WrappedNavigableSet(
        @ParametricNullness K key, NavigableSet<V> delegate, @Nullable WrappedCollection ancestor) {
      super(key, delegate, ancestor);
    }

    @Override
    NavigableSet<V> getSortedSetDelegate() {
      return (NavigableSet<V>) super.getSortedSetDelegate();
    }

    @Override

  public Test testsForCheckedNavigableSet() {
    return SortedSetTestSuiteBuilder.using(
            new TestStringSortedSetGenerator() {
              @Override
              public NavigableSet<String> create(String[] elements) {
                NavigableSet<String> innerSet = new TreeSet<>();
                Collections.addAll(innerSet, elements);
                return Collections.checkedNavigableSet(innerSet, String.class);
              }

      List<String> list = Lists.newArrayList(elements);
      list.add("\0");
      list.add("zzz");
      return ImmutableSortedSet.copyOf(list).subSet("\0\0", "zzy");
    }
  }

  @GwtIncompatible // NavigableSet
  public static class ImmutableSortedSetDescendingGenerator extends TestStringSortedSetGenerator {
    @Override
    protected SortedSet<String> create(String[] elements) {

    suite.addTest(
        NavigableSetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override
                  public NavigableSet<String> create(String[] elements) {
                    NavigableSet<String> unfiltered = Sets.newTreeSet();
                    unfiltered.add("yyy");
                    unfiltered.addAll(ImmutableList.copyOf(elements));

import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NavigableSet;
import java.util.SortedSet;
import java.util.stream.Collector;
import org.jspecify.annotations.Nullable;

/**
 * A {@link NavigableSet} whose contents will never change, with many other important properties
 * detailed at {@link ImmutableCollection}.
 *

package com.google.common.collect;

import static com.google.common.collect.Maps.keyOrNull;

import com.google.common.annotations.GwtIncompatible;
import java.util.Iterator;
import java.util.NavigableMap;
import java.util.NavigableSet;
import java.util.NoSuchElementException;
import java.util.SortedMap;
import org.jspecify.annotations.Nullable;

/**
 * A navigable map which forwards all its method calls to another navigable map. Subclasses should

package com.google.common.collect;

import static com.google.common.collect.Maps.keyOrNull;

import com.google.common.annotations.GwtIncompatible;
import java.util.Iterator;
import java.util.NavigableMap;
import java.util.NavigableSet;
import java.util.NoSuchElementException;
import java.util.SortedMap;
import java.util.function.BiFunction;
import org.jspecify.annotations.Nullable;

/**

      List<String> list = Lists.newArrayList(elements);
      list.add("\0");
      list.add("zzz");
      return ImmutableSortedSet.copyOf(list).subSet("\0\0", "zzy");
    }
  }

  @GwtIncompatible // NavigableSet
  public static class ImmutableSortedSetDescendingGenerator extends TestStringSortedSetGenerator {
    @Override
    protected SortedSet<String> create(String[] elements) {

import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;
import java.util.NavigableMap;
import java.util.NavigableSet;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.concurrent.ConcurrentMap;