code: public ChronologyType getChronologyType()
      {
          final String chronoKey = this.attrValues.get(Person.AttrName.CHRONOLOGY);
          final ChronologyType chronoType;
          if (chronoKey != null) {
              chronoType = ChronologyType.getByKey(chronoKey);
          } else {
              chronoType = ChronologyType.ISO8601;
          }
          return chronoType;
      }
docs: Method to get the ChronologyType of this Person. Default is the "ISO8601"
  ChronologyType.
  
  @return ChronologyType of this Person