@abc.abstractmethod<EOL><INDENT>def assign_superseding_event_to_calendar(self, superseding_event_id, calendar_id):<DEDENT>
pass<EOL>
Adds an existing ``SupersedingEvent`` to a ``Calendar``.

        :param superseding_event_id: the ``Id`` of the ``SupersedingEvent``
        :type superseding_event_id: ``osid.id.Id``
        :param calendar_id: the ``Id`` of the ``Calendar``
        :type calendar_id: ``osid.id.Id``
        :raise: ``AlreadyExists`` -- ``superseding_event_id`` is already assigned to ``calendar_id``
        :raise: ``NotFound`` -- ``superseding_event_id`` or ``calendar_id`` not found
        :raise: ``NullArgument`` -- ``superseding_event_id`` or ``calendar_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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