@Override
  protected void addReceived(long rv) {
    if (received == null) {
      received = new TreeSet<>();
    }
    received.add(rv);
  }
This subclass of RVVException is the original class that uses TreeSets to hold received versions.
It is now only used if the exception represents a large gap.
geode-core/src/main/java/org/apache/geode/internal/cache/versions/RVVExceptionT.java