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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_time_graded(self):
 """Gets the time the gradeable object was graded. return: (osid.calendaring.DateTime) - the timestamp of the grading entry raise: IllegalState - ``is_graded()`` is ``false`` or ``is_derived()`` is ``true`` *compliance: mandatory -- This method must be implemented.* """

        if not self.is_graded() or self.is_derived():
            raise errors.IllegalState()
        time_graded = self._my_map['timeGraded']
        return DateTime(
            year=time_graded.year,
            month=time_graded.month,
            day=time_graded.day,
            hour=time_graded.hour,
            minute=time_graded.minute,
            second=time_graded.second,
            microsecond=time_graded.microsecond)