@abc.abstractmethod<EOL><INDENT>def get_schedule_slot_notification_session_for_calendar(self, schedule_slot_receiver, calendar_id, proxy):<DEDENT>
return<EOL>
Gets the ``OsidSession`` associated with the schedule slot notification service for the given calendar.

        :param schedule_slot_receiver: the schedule slot receiver
        :type schedule_slot_receiver: ``osid.calendaring.ScheduleSlotReceiver``
        :param calendar_id: the ``Id`` of the calendar
        :type calendar_id: ``osid.id.Id``
        :param proxy: a proxy
        :type proxy: ``osid.proxy.Proxy``
        :return: a ``ScheduleSlotNotificationSession``
        :rtype: ``osid.calendaring.ScheduleSlotNotificationSession``
        :raise: ``NotFound`` -- ``calendar_id`` not found
        :raise: ``NullArgument`` -- ``schedule_slot_receiver, calendar_id`` or ``proxy`` is ``null``
        :raise: ``OperationFailed`` -- ``unable to complete request``
        :raise: ``Unimplemented`` -- ``supports_schedule_slot_notification()`` or ``supports_visible_federation()`` is
        ``false``

        *compliance: optional -- This method must be implemented if
        ``supports_schedule_slot_notification()`` and
        ``supports_visible_federation()`` are ``true``.*