code: def get_objective_bank_form_for_update(self, objective_bank_id=None):
          
          if objective_bank_id is None:
              raise NullArgument()
          try:
              url_path = construct_url('objective_banks',
                                       bank_id=objective_bank_id)
              objective_bank = objects.ObjectiveBank(self._get_request(url_path))
          except Exception:
              raise
          objective_bank_form = objects.ObjectiveBankForm(objective_bank._my_map)
          self._forms[objective_bank_form.get_id().get_identifier()] = not UPDATED
          return objective_bank_form
docs: Gets the objective bank form for updating an existing objective
          bank.
          A new objective bank form should be requested for each update
          transaction.
          arg:    objectiveBankId (osid.id.Id): the Id of the
                  ObjectiveBank
          return: (osid.learning.ObjectiveBankForm) - the objective bank
                  form
          raise:  NotFound - objectiveBankId is not found
          raise:  NullArgument - objectiveBankId is null
          raise:  OperationFailed - unable to complete request
          raise:  PermissionDenied - authorization failure
          compliance: mandatory - This method must be implemented.