code: public DateTime toDateTime(Chronology chronology) {
          chronology = DateTimeUtils.getChronology(chronology);
          if (getChronology() == chronology) {
              return this;
          }
          return super.toDateTime(chronology);
      }
docs: Get this object as a DateTime, returning <code>this</code> if possible.
  
  @param chronology chronology to apply, or ISOChronology if null
  @return a DateTime using the same millis