@Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + entryVersion;
    result = prime * result + ((memberID == null) ? 0 : memberID.hashCode());
    result = prime * result + regionVersionHighBytes;
    result = prime * result + regionVersionLowBytes;
    if (isGatewayTag()) {
      result = prime * result + (int) timeStamp;
      result = prime * result + (int) (timeStamp >>> 32);
    }
    return result;
  }
Creates a version tag of the appropriate type, based on the member id
geode-core/src/main/java/org/apache/geode/internal/cache/versions/VersionTag.java