if (i == null) {
      return 0;
    }

    return i.getAndSet(count);
  }

  // Don't allow default serialization.
  @GwtIncompatible
  @J2ktIncompatible
    private void readObjectNoData() throws ObjectStreamException {
    throw new InvalidObjectException("Stream data required");
  }

  @GwtIncompatible @J2ktIncompatible   private static final long serialVersionUID = -2250766705698539974L;