}

  public static class Strings extends SampleElements<String> {
    public Strings() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super("b", "a", "c", "d", "e");
    }

    // for testing SortedSet and SortedMap methods
    public static final String BEFORE_FIRST = "\0";
    public static final String BEFORE_FIRST_2 = "\0\0";

  }

  private static <E extends @Nullable Object> SortedSet<E> sortedSet(
      SortedSet<E> set, @Nullable Object mutex) {
    return new SynchronizedSortedSet<>(set, mutex);
  }

  static class SynchronizedSortedSet<E extends @Nullable Object> extends SynchronizedSet<E>
      implements SortedSet<E> {
    SynchronizedSortedSet(SortedSet<E> delegate, @Nullable Object mutex) {
      super(delegate, mutex);
    }

  }

  private static <E extends @Nullable Object> SortedSet<E> sortedSet(
      SortedSet<E> set, @Nullable Object mutex) {
    return new SynchronizedSortedSet<>(set, mutex);
  }

  static class SynchronizedSortedSet<E extends @Nullable Object> extends SynchronizedSet<E>
      implements SortedSet<E> {
    SynchronizedSortedSet(SortedSet<E> delegate, @Nullable Object mutex) {
      super(delegate, mutex);
    }

    assertTrue(multimap.keySet() instanceof SortedSet);
    assertTrue(multimap.asMap() instanceof SortedMap);
  }

  public void testTreeKeys_gwtCompatible() {
    ListMultimap<String, Integer> multimap =
        rawtypeToWildcard(MultimapBuilder.treeKeys()).arrayListValues().<String, Integer>build();
    assertTrue(multimap.keySet() instanceof SortedSet);
    assertTrue(multimap.asMap() instanceof SortedMap);
  }

        TestSortedSetGenerator<E> delegate, Bound to, Bound from) {
      super(delegate, to, from);
    }

    @Override
    NavigableSet<E> createSubSet(SortedSet<E> sortedSet, E firstExclusive, E lastExclusive) {
      NavigableSet<E> set = (NavigableSet<E>) sortedSet;
      if (from == Bound.NO_BOUND && to == Bound.INCLUSIVE) {
        return set.headSet(lastInclusive, true);

    }
  }

  /** SortedSet decorator that stays in sync with the multimap values for a key. */
  @WeakOuter
  class WrappedSortedSet extends WrappedCollection implements SortedSet<V> {
    WrappedSortedSet(
        @ParametricNullness K key, SortedSet<V> delegate, @Nullable WrappedCollection ancestor) {
      super(key, delegate, ancestor);
    }

    SortedSet<V> getSortedSetDelegate() {

 */

package com.google.common.collect.testing;

import static java.util.Collections.sort;

import com.google.common.annotations.GwtCompatible;
import java.util.List;
import java.util.SortedSet;
import org.jspecify.annotations.NullMarked;

/**
 * Create integer sets for testing collections that are sorted by natural ordering.
 *
 * @author Chris Povirk
 * @author Jared Levy
 */
@GwtCompatible

  }

  public void testFirst_sortedSet() {
    SortedSet<String> sortedSet = ImmutableSortedSet.of("b", "c", "a");
    assertThat(FluentIterable.from(sortedSet).first()).hasValue("a");
  }

  public void testFirst_emptySortedSet() {
    SortedSet<String> sortedSet = ImmutableSortedSet.of();
    assertThat(FluentIterable.from(sortedSet).first()).isAbsent();
  }

  public void testFirst_iterable() {

    }

    @Override
    public @Nullable T pollLast() {
      return standardPollLast();
    }

    @Override
    public SortedSet<T> headSet(T toElement) {
      return standardHeadSet(toElement);
    }

    @Override
    public SortedSet<T> tailSet(T fromElement) {
      return standardTailSet(fromElement);
    }
  }

  @AndroidIncompatible // test-suite builders

 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtIncompatible;
import java.util.Iterator;
import java.util.NavigableSet;
import java.util.SortedSet;
import org.jspecify.annotations.Nullable;

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