.test();
  }

  public void testPairwiseEquivalent_equals() {
    new EqualsTester()
        .addEqualityGroup(Equivalence.equals().pairwise(), Equivalence.equals().pairwise())
        .addEqualityGroup(Equivalence.identity().pairwise())
        .testEquals();
  }

  private enum LengthFunction implements Function<String, Integer> {
    INSTANCE;

    @Override
    public Integer apply(String input) {

    return false;
  }

  @Override
  public int hashCode() {
    return elementEquivalence.hashCode() ^ 0x46a3eb07;
  }

  @Override
  public String toString() {
    return elementEquivalence + ".pairwise()";
  }

  @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 1;

    return false;
  }

  @Override
  public int hashCode() {
    return elementEquivalence.hashCode() ^ 0x46a3eb07;
  }

  @Override
  public String toString() {
    return elementEquivalence + ".pairwise()";
  }

  @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 1;

 * @author Louis Wasserman
 */
@GwtCompatible
public final class Comparators {
  private Comparators() {}

  /**
   * Returns a new comparator which sorts iterables by comparing corresponding elements pairwise
   * until a nonzero result is found; imposes "dictionary order." If the end of one iterable is
   * reached, but not the other, the shorter iterable is considered to be less than the longer one.

   *
   * <p>The returned object is serializable if this object is serializable.
   *
   * @since 10.0
   */
  public final <S extends @Nullable T> Equivalence<Iterable<S>> pairwise() {
    // Ideally, the returned equivalence would support Iterable<? extends T>. However,
    // the need for this is so rare that it's not worth making callers deal with the ugly wildcard.

      Iterable<? extends Comparator<? super T>> comparators) {
    return new CompoundOrdering<>(comparators);
  }

  /**
   * Returns a new ordering which sorts iterables by comparing corresponding elements pairwise until
   * a nonzero result is found; imposes "dictionary order". If the end of one iterable is reached,
   * but not the other, the shorter iterable is considered to be less than the longer one. For