code: def get_objectives_by_objective_banks(self, objective_bank_ids):
          
          # Implemented from template for
          # osid.resource.ResourceBinSession.get_resources_by_bins
          objective_list = []
          for objective_bank_id in objective_bank_ids:
              objective_list += list(
                  self.get_objectives_by_objective_bank(objective_bank_id))
          return objects.ObjectiveList(objective_list)
docs: Gets the list of ``Objectives`` corresponding to a list of ``ObjectiveBanks``.
  
          arg:    objective_bank_ids (osid.id.IdList): list of objective
                  bank ``Ids``
          return: (osid.learning.ObjectiveList) - list of objectives
          raise:  NullArgument - ``objective_bank_ids`` is ``null``
          raise:  OperationFailed - unable to complete request
          raise:  PermissionDenied - authorization failure
          *compliance: mandatory -- This method must be implemented.*