@abc.abstractmethod<EOL><INDENT>def sequence_objectives(self, parent_objective_id, objective_ids):<DEDENT>
pass<EOL>
Sequences a set of objectives under a parent.

        :param parent_objective_id: the ``Id`` of the parent objective
        :type parent_objective_id: ``osid.id.Id``
        :param objective_ids: the ``Id`` of the objectives
        :type objective_ids: ``osid.id.Id[]``
        :raise: ``NotFound`` -- ``parent_id`` or an ``objective_id`` not found, or an ``objective_id`` is not a child of ``parent_objective_id``
        :raise: ``NullArgument`` -- ``paren_objectivet_id`` or ``objective_ids`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

        *compliance: mandatory -- This method must be implemented.*