@Override
  public String toString() {
    if (received != null) {
      return "e(n=" + nextVersion + " p=" + +previousVersion
          + (received.size() == 0 ? "" : "; rs=" + received) + ")";
    }
    return "et(n=" + nextVersion + " p=" + previousVersion + "; rs=[])";
  }
checks to see if any of the received versions can be merged into the start/end version numbers
geode-core/src/main/java/org/apache/geode/internal/cache/versions/RVVExceptionT.java