}

  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() {

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

/**
 * Superinterface of {@link SortedMultiset} to introduce a bridge method for {@code elementSet()},
 * to ensure binary compatibility with older Guava versions that specified {@code elementSet()} to
 * return {@code SortedSet}.
 *
 * @author Louis Wasserman
 */
@GwtIncompatible

        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);

    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);
  }

   * <p>This method is safe to use even when {@code sortedSet} is a synchronized or concurrent
   * collection that is currently being modified by another thread.
   *
   * @throws NullPointerException if {@code sortedSet} or any of its elements is null
   */
  public static <E> ImmutableSortedSet<E> copyOfSorted(SortedSet<E> sortedSet) {
    Comparator<? super E> comparator = SortedIterables.comparator(sortedSet);

    }

    @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

    }
  }

  /** 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() {

        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() {

 * 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