this.instance = instance;
    }

    @Override
    @ParametricNullness
    public T get() {
      return instance;
    }

    @Override
    public boolean equals(@CheckForNull Object obj) {
      if (obj instanceof SupplierOfInstance) {
        SupplierOfInstance<?> that = (SupplierOfInstance<?>) obj;
        return Objects.equal(instance, that.instance);
      }
      return false;
    }

    BigInteger offset(BigInteger origin, long distance) {
      checkNonnegative(distance, "distance");
      return origin.add(BigInteger.valueOf(distance));
    }

    @Override
    public long distance(BigInteger start, BigInteger end) {
      return end.subtract(start).max(MIN_LONG).min(MAX_LONG).longValue();
    }

    private Object readResolve() {
      return INSTANCE;
    }

    @Override

      return INSTANCE;
    }

    private static final long serialVersionUID = 0;
  }

  /*
   * The implementation neither produces nor consumes any non-null instance of
   * type C, so casting the type parameter is safe.
   */
  @SuppressWarnings("unchecked")
  static <C extends Comparable> Cut<C> aboveAll() {
    return (Cut<C>) AboveAll.INSTANCE;
  }

  public <E extends Comparable<?>> E min(E a, E b) {
    return NaturalOrdering.INSTANCE.max(a, b);
  }

  @Override
  public <E extends Comparable<?>> E min(E a, E b, E c, E... rest) {
    return NaturalOrdering.INSTANCE.max(a, b, c, rest);
  }

  @Override
  public <E extends Comparable<?>> E min(Iterator<E> iterator) {
    return NaturalOrdering.INSTANCE.max(iterator);
  }

  @Override

    for (Class<?> mutableClass : mutableClasses) {
      Object instance = ArbitraryInstances.get(mutableClass);
      assertNotNull("Expected to return non-null for: " + mutableClass, instance);
      assertNotSame(
          "Expected to return fresh instance for: " + mutableClass,
          instance,
          ArbitraryInstances.get(mutableClass));
    }
  }

  private enum EmptyEnum {}

  }

  private <T> T pickInstance(T[] instances, T defaultValue) {
    return pickInstance(Arrays.asList(instances), defaultValue);
  }

  private <T> T pickInstance(Collection<T> instances, T defaultValue) {
    if (instances.isEmpty()) {
      return defaultValue;
    }
    // generateInt() is 1-based.
    return Iterables.get(instances, (generateInt() - 1) % instances.size());
  }

    this.valueTypeOrObjectUnderJ2cl = valueTypeOrObjectUnderJ2cl;
  }

  static <K extends Enum<K>> Class<K> inferKeyTypeOrObjectUnderJ2cl(Map<K, ?> map) {
    if (map instanceof EnumBiMap) {
      return ((EnumBiMap<K, ?>) map).keyTypeOrObjectUnderJ2cl;
    }
    if (map instanceof EnumHashBiMap) {
      return ((EnumHashBiMap<K, ?>) map).keyTypeOrObjectUnderJ2cl;
    }
    checkArgument(!map.isEmpty());

   */
  @GwtIncompatible // Class.cast, Class.isInstance
  public static <X extends Throwable> void throwIfInstanceOf(
      Throwable throwable, Class<X> declaredType) throws X {
    checkNotNull(throwable);
    if (declaredType.isInstance(throwable)) {
      throw declaredType.cast(throwable);
    }
  }

  /**
   * Propagates {@code throwable} exactly as-is, if and only if it is an instance of {@code
   * declaredType}. Example usage:

   */
  @GwtIncompatible // Class.cast, Class.isInstance
  public static <X extends Throwable> void throwIfInstanceOf(
      Throwable throwable, Class<X> declaredType) throws X {
    checkNotNull(throwable);
    if (declaredType.isInstance(throwable)) {
      throw declaredType.cast(throwable);
    }
  }

  /**
   * Propagates {@code throwable} exactly as-is, if and only if it is an instance of {@code
   * declaredType}. Example usage:

  }

  private static GetCheckedTypeValidator nonCachingWithoutConstructorCheckValidator() {
    return NonCachingWithoutConstructorCheckValidator.INSTANCE;
  }

  private enum NonCachingWithoutConstructorCheckValidator implements GetCheckedTypeValidator {
    INSTANCE;

    @Override
    public void validateClass(Class<? extends Exception> exceptionClass) {
      checkArgument(