public static <T extends @Nullable Object, S extends T> Comparator<Iterable<S>> lexicographical(
      Comparator<T> comparator) {
    return new LexicographicalOrdering<S>(checkNotNull(comparator));
  }

  /**
   * Returns {@code true} if each element in {@code iterable} after the first is greater than or
   * equal to the element that preceded it, according to the specified comparator. Note that this is

  public static <T extends @Nullable Object, S extends T> Comparator<Iterable<S>> lexicographical(
      Comparator<T> comparator) {
    return new LexicographicalOrdering<S>(checkNotNull(comparator));
  }

  /**
   * Returns {@code true} if each element in {@code iterable} after the first is greater than or
   * equal to the element that preceded it, according to the specified comparator. Note that this is

/**
 * Tests for {@code Comparators}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class ComparatorsTest extends TestCase {
  public void testLexicographical() {
    Comparator<String> comparator = Ordering.natural();
    Comparator<Iterable<String>> lexy = Comparators.lexicographical(comparator);

    ImmutableList<String> empty = ImmutableList.of();

  }

  public void testMinMaxComparator() {
    Comparator<Integer> natural = Ordering.natural();
    Comparator<Integer> reverse = Collections.reverseOrder(natural);
    assertThat(Comparators.min(1, 2, reverse)).isEqualTo(2);
    assertThat(Comparators.min(2, 1, reverse)).isEqualTo(2);
    assertThat(Comparators.max(1, 2, reverse)).isEqualTo(1);
    assertThat(Comparators.max(2, 1, reverse)).isEqualTo(1);
  }

  /**

  }

  TreeMultimap(Comparator<? super K> keyComparator, Comparator<? super V> valueComparator) {
    super(new TreeMap<K, Collection<V>>(keyComparator));
    this.keyComparator = keyComparator;
    this.valueComparator = valueComparator;
  }

  private TreeMultimap(
      Comparator<? super K> keyComparator,
      Comparator<? super V> valueComparator,

  }

  /** Create and populate a {@code TreeMultimap} with explicit comparators. */
  private TreeMultimap<@Nullable String, @Nullable Integer> createPopulate() {
    TreeMultimap<@Nullable String, @Nullable Integer> multimap =
        TreeMultimap.create(StringLength.COMPARATOR, DECREASING_INT_COMPARATOR);
    multimap.put("google", 2);
    multimap.put("google", 6);

  final Comparator<? super T>[] comparators;

  @SuppressWarnings("unchecked") // Generic array creation
  CompoundOrdering(Comparator<? super T> primary, Comparator<? super T> secondary) {
    this.comparators = (Comparator<? super T>[]) new Comparator<?>[] {primary, secondary};
  }

  @SuppressWarnings("unchecked") // Generic array creation
  CompoundOrdering(Iterable<? extends Comparator<? super T>> comparators) {

  final Comparator<? super T>[] comparators;

  @SuppressWarnings("unchecked") // Generic array creation
  CompoundOrdering(Comparator<? super T> primary, Comparator<? super T> secondary) {
    this.comparators = (Comparator<? super T>[]) new Comparator<?>[] {primary, secondary};
  }

  @SuppressWarnings("unchecked") // Generic array creation
  CompoundOrdering(Iterable<? extends Comparator<? super T>> comparators) {

    return unsafeComparator.compare(a, b);
  }

  final transient Comparator<? super E> comparator;

  ImmutableSortedSet(Comparator<? super E> comparator) {
    this.comparator = comparator;
  }

  /**
   * Returns the comparator that orders the elements, which is {@link Ordering#natural()} when the

   * the given {@code comparator}.
   *
   * @see #testComparator(Comparator, List)
   */
  public static <T extends @Nullable Object> void testComparator(
      Comparator<? super T> comparator, T... valuesInExpectedOrder) {
    testComparator(comparator, Arrays.asList(valuesInExpectedOrder));
  }

  /**