new NumberFormatException("Error parsing value: " + stringValue);
      decodeException.initCause(e);
      throw decodeException;
    }
  }

  /*
   * We move the static constants into this class so ProGuard can inline UnsignedLongs entirely
   * unless the user is actually calling a parse method.
   */
  private static final class ParseOverflowDetection {
    private ParseOverflowDetection() {}

      String objectToString =
          o.getClass().getName() + '@' + Integer.toHexString(System.identityHashCode(o));
      // Logger is created inline with fixed name to avoid forcing Proguard to create another class.
      Logger.getLogger("com.google.common.base.Strings")
          .log(WARNING, "Exception during lenientFormat for " + objectToString, e);

    ImmutableSet<K> result = keySet;
    return (result == null) ? keySet = createKeySet() : result;
  }

  /*
   * This could have a good default implementation of return new ImmutableKeySet<K, V>(this),
   * but ProGuard can't figure out how to eliminate that default when RegularImmutableMap
   * overrides it.
   */
  abstract ImmutableSet<K> createKeySet();

  UnmodifiableIterator<K> keyIterator() {

    return (result == null) ? keySet = createKeySet() : result;
  }

  /*
   * This could have a good default implementation of return new ImmutableKeySet<K, V>(this),
   * but ProGuard can't figure out how to eliminate that default when RegularImmutableMap
   * overrides it.
   */
  abstract ImmutableSet<K> createKeySet();

  UnmodifiableIterator<K> keyIterator() {

      result.descendingSet = this;
    }
    return result;
  }

  // Most classes should implement this as new DescendingImmutableSortedSet<E>(this),
  // but we push down that implementation because ProGuard can't eliminate it even when it's always
  // overridden.
  @GwtIncompatible // NavigableSet
  abstract ImmutableSortedSet<E> createDescendingSet();

  /**
   * @since 12.0
   */

  static <T extends @Nullable Object> UnmodifiableListIterator<T> emptyListIterator() {
    return (UnmodifiableListIterator<T>) ArrayItr.EMPTY;
  }

  /**
   * This is an enum singleton rather than an anonymous class so ProGuard can figure out it's only
   * referenced by emptyModifiableIterator().
   */
  private enum EmptyModifiableIterator implements Iterator<Object> {
    INSTANCE;

    @Override
    public boolean hasNext() {