// actually implement BiPredicate, and CollectorTests expects a BiPredicate.
  static <C, E extends @Nullable Object, R extends Iterable<E>>
      BiPredicate<C, C> pairwiseOnResultOf(Function<C, R> arg) {
    Equivalence<C> equivalence = Equivalence.equals().<E>pairwise().onResultOf(arg);
    return equivalence::equivalent;
  }

- Server Side Apply now treats LabelSelector...

    assertTrue(ArbitraryInstances.get(Predicate.class).apply("abc"));
    assertTrue(ArbitraryInstances.get(Equivalence.class).equivalent(1, 1));
    assertFalse(ArbitraryInstances.get(Equivalence.class).equivalent(1, 2));
  }

  @SuppressWarnings("SelfComparison")
  public void testGet_comparable() {
    @SuppressWarnings("unchecked") // The null value can compare with any Object

  @CanIgnoreReturnValue
  CacheBuilder<K, V> keyEquivalence(Equivalence<Object> equivalence) {
    checkState(keyEquivalence == null, "key equivalence was already set to %s", keyEquivalence);
    keyEquivalence = checkNotNull(equivalence);
    return this;
  }

  Equivalence<Object> getKeyEquivalence() {
    return MoreObjects.firstNonNull(keyEquivalence, getKeyStrength().defaultEquivalence());
  }

  /**

    assertTrue(ArbitraryInstances.get(Predicate.class).apply("abc"));
    assertTrue(ArbitraryInstances.get(Equivalence.class).equivalent(1, 1));
    assertFalse(ArbitraryInstances.get(Equivalence.class).equivalent(1, 2));
  }

  @SuppressWarnings("SelfComparison")
  public void testGet_comparable() {
    @SuppressWarnings("unchecked") // The null value can compare with any Object

   * stream is empty.
   *
   * <p>Equivalent to {@code stream.reduce((a, b) -> b)}, but may perform significantly better. This
   * method's runtime will be between O(log n) and O(n), performing better on <a
   * href="http://gee.cs.oswego.edu/dl/html/StreamParallelGuidance.html">efficiently splittable</a>
   * streams.
   *
   * <p>If the stream has nondeterministic order, this has equivalent semantics to {@link

   * that of {@code ((Integer) a).compareTo(b)}.
   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated; use the
   * equivalent {@link Integer#compare} method instead.
   *
   * @param a the first {@code int} to compare
   * @param b the second {@code int} to compare

  }

  protected void initMapWithNullKey() {
    resetMap(createArrayWithNullKey());
  }

  protected void initMapWithNullValue() {
    resetMap(createArrayWithNullValue());
  }

  /**
   * Equivalent to {@link #expectMissingKeys(Object[]) expectMissingKeys} {@code (null)} except that
   * the call to {@code contains(null)} is permitted to throw a {@code NullPointerException}.
   *

      }
      return builder.build();
    }

    /**
     * Copies the current contents of this set view into an existing set. This method has equivalent
     * behavior to {@code set.addAll(this)}, assuming that all the sets involved are based on the
     * same notion of equivalence.
     *
     * @return a reference to {@code set}, for convenience
     */
    // Note: S should logically extend Set<? super E> but can't due to either

  @CanIgnoreReturnValue
  @Override
  Hasher putLong(long l);

  /** Equivalent to {@code putInt(Float.floatToRawIntBits(f))}. */
  @CanIgnoreReturnValue
  @Override
  Hasher putFloat(float f);

  /** Equivalent to {@code putLong(Double.doubleToRawLongBits(d))}. */
  @CanIgnoreReturnValue
  @Override
  Hasher putDouble(double d);

  /** Equivalent to {@code putByte(b ? (byte) 1 : (byte) 0)}. */
  @CanIgnoreReturnValue