code: def replace(self, year=None, month=None, day=None):
          
  
          return JalaliDate(
              year if year else self.year,
              month if month else self.month,
              day if day else self.day
          )
docs: Replaces the given arguments on this instance, and return a new instance.
  
          :param year:
          :param month:
          :param day:
          :return: A :py:class:`khayyam.JalaliDate` with the same attributes, except for those
              attributes given new values by which keyword arguments are specified.