private void format() {
    StringBuilder sb = new StringBuilder();
    sb.append(country != null ? country.name() : "")
      .append(":")
      .append(organisation != null ? organisation : "")
      .append(":")
      .append(datasetType != null ? datasetType.name() : "")
      .append(":")
      .append(serial != null ? serial : uuidSnippet());
    this.value = sb.toString();
  }