@abc.abstractmethod<EOL><INDENT>def move_objective_behind(self, parent_objective_id, reference_objective_id, objective_id):<DEDENT>
pass<EOL>
Moves an objective behind a refrence objective under the given parent.

        :param parent_objective_id: the ``Id`` of the parent objective
        :type parent_objective_id: ``osid.id.Id``
        :param reference_objective_id: the ``Id`` of the objective
        :type reference_objective_id: ``osid.id.Id``
        :param objective_id: the ``Id`` of the objective to move behind ``reference_objective_id``
        :type objective_id: ``osid.id.Id``
        :raise: ``NotFound`` -- ``parent_objective_id, reference_objective_id,`` or ``objective_id`` not found, or ``reference_objective_id`` or ``objective_id`` is not a child of ``parent_objective_id``
        :raise: ``NullArgument`` -- ``parent_objective_id, reference_objective_id,`` or ``id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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