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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_child_assessment_parts(self):
 """Gets any child assessment parts. return: (osid.assessment.authoring.AssessmentPartList) - the child assessment parts raise: OperationFailed - unable to complete request *compliance: mandatory -- This method must be implemented.* """

        if not self.has_children():
            raise errors.IllegalState('no children assessment parts')
        # only returned unsequestered children?
        lookup_session = self._get_assessment_part_lookup_session()
        lookup_session.use_sequestered_assessment_part_view()
        return lookup_session.get_assessment_parts_by_ids(self.get_child_ids())