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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_assessment_part(self, assessment_part_id):
 """Gets the ``AssessmentPart`` specified by its ``Id``. arg: assessment_part_id (osid.id.Id):
 the ``Id`` of the ``AssessmentPart`` to retrieve return: (osid.assessment.authoring.AssessmentPart) - the returned ``AssessmentPart`` raise: NotFound - no ``AssessmentPart`` found with the given ``Id`` raise: NullArgument - ``assessment_part_id`` is ``null`` raise: OperationFailed - unable to complete request raise: PermissionDenied - authorization failure *compliance: mandatory -- This method must be implemented.* """

        # Implemented from template for
        # osid.resource.ResourceLookupSession.get_resource
        # NOTE: This implementation currently ignores plenary view
        collection = JSONClientValidated('assessment_authoring',
                                         collection='AssessmentPart',
                                         runtime=self._runtime)
        result = collection.find_one(
            dict({'_id': ObjectId(self._get_id(assessment_part_id, 'assessment_authoring').get_identifier())},
                 **self._view_filter()))
        return objects.AssessmentPart(osid_object_map=result, runtime=self._runtime, proxy=self._proxy)