private void setBits(int bitMask) {
    int oldBits;
    int newBits;
    do {
      oldBits = bits;
      newBits = oldBits | bitMask;
    } while (!bitsUpdater.compareAndSet(this, oldBits, newBits));
  }
Set any bits in the given bitMask on the bits field
geode-core/src/main/java/org/apache/geode/internal/cache/versions/VersionTag.java