@abc.abstractmethod<EOL><INDENT>def get_offset_event_admin_session(self):<DEDENT>
return<EOL>
Gets the ``OsidSession`` associated with the offset event administration service.

        :return: an ``OffsetEventAdminSession``
        :rtype: ``osid.calendaring.OffsetEventAdminSession``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_offset_event_admin()`` is ``false``

        *compliance: optional -- This method must be implemented if
        ``supports_offset_event_admin()`` is ``true``.*