@abc.abstractmethod<EOL><INDENT>def get_commitments_for_event_and_resource(self, event_id, resource_id):<DEDENT>
return<EOL>
Gets the commitments for the given event and resource.

        If the event is a recurring event, the commitments are returned
        for the recurring event only.

        In plenary mode, the returned list contains all of the
        commitments mapped to the event ``Id`` or an error results if an
        Id in the supplied list is not found or inaccessible. Otherwise,
        inaccessible ``Commitments`` may be omitted from the list and
        may present the elements in any order including returning a
        unique set.

        In effective mode, commitments are returned that are currently
        effective. In any effective mode, effective commitments and
        those currently expired are returned.

        :param event_id: ``Id`` of the ``Event``
        :type event_id: ``osid.id.Id``
        :param resource_id: ``Id`` of a ``Resource``
        :type resource_id: ``osid.id.Id``
        :return: list of commitments
        :rtype: ``osid.calendaring.CommitmentList``
        :raise: ``NullArgument`` -- ``event_id`` or ``resource_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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