def get_agency_search_session(self):
raise Unimplemented()<EOL>
Gets the ``OsidSession`` associated with the agency search service.

        return: (osid.authentication.AgencySearchSession) - an
                ``AgencySearchSession``
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented - ``supports_agency_search()`` is
                ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_agency_search()`` is ``true``.*