code: function(year) {
          var date = this._validate(year, this.minMonth, this.minDay,
              main.local.invalidYear || main.regionalOptions[''].invalidYear);
          return gregorian.leapYear(date.year() + (date.year() < 1 ? 1 : 0) + 1469);
      }
docs: Determine whether this date is in a leap year.
  @memberof NanakshahiCalendar
  @param year {CDate|number} The date to examine or the year to examine.
  @return {boolean} <code>true</code> if this is a leap year, <code>false</code> if not.
  @throws Error if an invalid year or a different calendar used.