public boolean containsMember(T id) {
    if (memberToVersion.containsKey(id)) {
      return true;
    }
    if (memberToGCVersion.containsKey(id)) {
      return true;
    }
    return canonicalIds.containsKey(id);
  }
Test hook - does this vector hold an entry for the given ID?
geode-core/src/main/java/org/apache/geode/internal/cache/versions/RegionVersionVector.java