@abc.abstractmethod<EOL><INDENT>def get_offset_events_by_event(self, event_id):<DEDENT>
return<EOL>
Gets the ``OffsetEvents`` using the given event as a start or ending offset.

        :param event_id: ``Id`` of the related event
        :type event_id: ``osid.id.Id``
        :return: the offset events
        :rtype: ``osid.calendaring.OffsetEventList``
        :raise: ``NullArgument`` -- ``event_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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