<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def closest(self, dt1, dt2):
 """ Get the closest date from the instance. :type dt1: Date or date :type dt2: Date or date :rtype: Date """

        dt1 = self.__class__(dt1.year, dt1.month, dt1.day)
        dt2 = self.__class__(dt2.year, dt2.month, dt2.day)

        if self.diff(dt1).in_seconds() < self.diff(dt2).in_seconds():
            return dt1

        return dt2