def get_objectives_by_record_type(self, objective_record_type=None):
raise Unimplemented()<EOL>
Gets an ObjectiveList containing the given objective record
        Type.
        In plenary mode, the returned list contains all known objectives
        or an error results. Otherwise, the returned list may contain
        only those objectives that are accessible through this session.
        arg:    objectiveRecordType (osid.type.Type): an objective
                record type
        return: (osid.learning.ObjectiveList) - the returned Objective
                list
        raise:  NullArgument - objectiveRecordType is null
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        compliance: mandatory - This method must be implemented.