code: @Override
      public Symmetry010Date date(int prolepticYear, int month, int dayOfMonth) {
          return Symmetry010Date.of(prolepticYear, month, dayOfMonth);
      }
docs: Obtains a local date in Symmetry010 calendar system from the
  proleptic-year, month-of-year and day-of-month fields.
  
  @param prolepticYear  the proleptic-year
  @param month  the month-of-year
  @param dayOfMonth  the day-of-month
  @return the Symmetry010 local date, not null
  @throws DateTimeException if unable to create the date