@abc.abstractmethod<EOL><INDENT>def get_assignable_objective_bank_ids_for_activity(self, objective_bank_id, activity_id):<DEDENT>
return<EOL>
Gets a list of objective banks including and under the given objective bank node in which a specific activity can be assigned.

        :param objective_bank_id: the ``Id`` of the ``ObjectiveBank``
        :type objective_bank_id: ``osid.id.Id``
        :param activity_id: the ``Id`` of the ``Activity``
        :type activity_id: ``osid.id.Id``
        :return: list of assignable objective bank ``Ids``
        :rtype: ``osid.id.IdList``
        :raise: ``NullArgument`` -- ``activity_id`` or ``objective_bank_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request

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