code: def get_assessment_part_bank_assignment_session(self):
          
          if not self.supports_assessment_part_bank_assignment():
              raise errors.Unimplemented()
          # pylint: disable=no-member
          return sessions.AssessmentPartBankAssignmentSession(runtime=self._runtime)
docs: Gets the ``OsidSession`` associated with assigning assessment part to bank.
  
          return:
                  (osid.assessment.authoring.AssessmentPartBankAssignmentS
                  ession) - an ``AssessmentPartBankAssignmentSession``
          raise:  OperationFailed - unable to complete request
          raise:  Unimplemented -
                  ``supports_assessment_part_bank_assignment()`` is
                  ``false``
          *compliance: optional -- This method must be implemented if
          ``supports_assessment_part_bank_assignment()`` is ``true``.*