code: @Override
      public JapaneseDate dateYearDay(Era era, int yearOfEra, int dayOfYear) {
          if (era instanceof JapaneseEra == false) {
              throw new ClassCastException("Era must be JapaneseEra");
          }
          return JapaneseDate.ofYearDay((JapaneseEra) era, yearOfEra, dayOfYear);
      }
docs: Obtains a local date in Japanese calendar system from the
  era, year-of-era and day-of-year fields.
  <p>
  The day-of-year in this factory is expressed relative to the start of the year-of-era.
  This definition changes the normal meaning of day-of-year only in those years
  where the year-of-era is reset to one due to a change in the era.
  For example:
  <pre>
  6th Jan Showa 64 = day-of-year 6
  7th Jan Showa 64 = day-of-year 7
  8th Jan Heisei 1 = day-of-year 1
  9th Jan Heisei 1 = day-of-year 2
  </pre>
  
  @param era  the Japanese era, not null
  @param yearOfEra  the year-of-era
  @param dayOfYear  the day-of-year
  @return the Japanese local date, not null
  @throws DateTimeException if unable to create the date
  @throws ClassCastException if the {@code era} is not a {@code JapaneseEra}