docs: public Chronology getChronology(Object object, Chronology chrono) {
          if (chrono != null) {
              return chrono;
          }
          Calendar cal = (Calendar) object;
          DateTimeZone zone = null;
          try {
              zone = DateTimeZone.forTimeZone(cal.getTimeZone());
              
          } catch (IllegalArgumentException ex) {
              zone = DateTimeZone.getDefault();
          }
          return getChronology(cal, zone);
      }