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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_start_time(self):
 """Gets the start time for this assessment. return: (osid.calendaring.DateTime) - the designated start time raise: IllegalState - ``has_start_time()`` is ``false`` *compliance: mandatory -- This method must be implemented.* """

        # Implemented from template for osid.assessment.AssessmentOffered.get_start_time_template
        if not bool(self._my_map['startTime']):
            raise errors.IllegalState()
        dt = self._my_map['startTime']
        return DateTime(dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second, dt.microsecond)