public final Predicate<@Nullable T> equivalentTo(@Nullable T target) {
    return new EquivalentToPredicate<>(this, target);
  }

  private static final class EquivalentToPredicate<T>
      implements Predicate<@Nullable T>, Serializable {

    private final Equivalence<T> equivalence;
    private final @Nullable T target;

    EquivalentToPredicate(Equivalence<T> equivalence, @Nullable T target) {