docs: long getFirstWeekOfYearMillis(int year) {
          long jan1millis = getYearMillis(year);
          int jan1dayOfWeek = getDayOfWeek(jan1millis);
          
          if (jan1dayOfWeek > (8 - iMinDaysInFirstWeek)) {
              // First week is end of previous year because it doesn't have enough days.
              return jan1millis + (8 - jan1dayOfWeek)
                  * (long)DateTimeConstants.MILLIS_PER_DAY;
          } else {
              // First week is start of this year because it has enough days.
              return jan1millis - (jan1dayOfWeek - 1)
                  * (long)DateTimeConstants.MILLIS_PER_DAY;
          }
      }