private static final class TreeSetSupplier<V extends @Nullable Object>
      implements Supplier<SortedSet<V>>, Serializable {
    private final Comparator<? super V> comparator;

    TreeSetSupplier(Comparator<? super V> comparator) {
      this.comparator = checkNotNull(comparator);
    }

    @Override
    public SortedSet<V> get() {
      return new TreeSet<>(comparator);
    }
  }

  private static final class TreeSetSupplier<V extends @Nullable Object>
      implements Supplier<SortedSet<V>>, Serializable {
    private final Comparator<? super V> comparator;

    TreeSetSupplier(Comparator<? super V> comparator) {
      this.comparator = checkNotNull(comparator);
    }

    @Override
    public SortedSet<V> get() {
      return new TreeSet<>(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 com.google.common.testing.SerializableTester;
import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.SortedSet;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit tests for {@code TreeMultimap} with explicit comparators.
 *

  }

  private static class NonNavigableSortedSet extends ForwardingSortedSet<String> {
    private final SortedSet<String> delegate = Sets.newTreeSet();

    @Override
    protected SortedSet<String> delegate() {
      return delegate;
    }
  }

  public void testAsMapSorted() {
    SortedSet<String> strings = new NonNavigableSortedSet();
    Collections.addAll(strings, "one", "two", "three");

      List<T> list = (List<T>) iterable;
      if (list.isEmpty()) {
        throw new NoSuchElementException();
      }
      return getLastInNonemptyList(list);
    } else if (iterable instanceof SortedSet) {
      return ((SortedSet<T>) iterable).last();
    }

    return Iterators.getLast(iterable.iterator());
  }

  /**
   * Returns the last element of {@code iterable} or {@code defaultValue} if the iterable is empty.

   */
  @Nullable Entry<E> pollLastEntry();

  /**
   * Returns a {@link NavigableSet} view of the distinct elements in this multiset.
   *
   * @since 14.0 (present with return type {@code SortedSet} since 11.0)
   */
  @Override
  NavigableSet<E> elementSet();

  /**
   * {@inheritDoc}
   *
   * <p>The {@code entrySet}'s iterator returns entries in ascending element order according to this

   */
  @Nullable Entry<E> pollLastEntry();

  /**
   * Returns a {@link NavigableSet} view of the distinct elements in this multiset.
   *
   * @since 14.0 (present with return type {@code SortedSet} since 11.0)
   */
  @Override
  NavigableSet<E> elementSet();

  /**
   * {@inheritDoc}
   *
   * <p>The {@code entrySet}'s iterator returns entries in ascending element order according to this

import java.util.Map;
import java.util.Map.Entry;
import java.util.NavigableSet;
import java.util.Queue;
import java.util.RandomAccess;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeSet;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@code Multimaps}.
 *