synchronized boolean contains(long v) {
    if (v > getVersion()) {
      return false;
    } else {
      if (bitSet != null && v >= bitSetVersion) {
        return bitSet.get((int) (v - bitSetVersion));
      }
      if (exceptions == null) {
        return true;
      }
      for (RVVException e : exceptions) {
        if (e.nextVersion <= v) {
          return true; // there is no RVVException for this version
        }
        if (e.previousVersion < v) {
          return e.contains(v);
        }
      }
      return true;
    }
  }
returns true if this version holder has seen the given version number
geode-core/src/main/java/org/apache/geode/internal/cache/versions/RegionVersionHolder.java