docs: public static DateTimeFormatter timeFormatterWithOptionalMilliseconds() {
          // This is the .SSS part
          DateTimeParser ms = new DateTimeFormatterBuilder()
                  .appendLiteral(".")
                  .appendFractionOfSecond(1, 3)
                  .toParser();
  
          return new DateTimeFormatterBuilder()
                  .append(DateTimeFormat.forPattern(ES_DATE_FORMAT_NO_MS).withZoneUTC())
                  .appendOptional(ms)
                  .toFormatter();
      }