def get_catalog_entry_notification_session(self, catalog_entry_receiver=None, proxy=None):
if proxy is None:<EOL><INDENT>raise NullArgument()<EOL><DEDENT>raise Unimplemented()<EOL>
Gets the catalog session for mapping ``Ids`` to ``Catalogs``.

        arg:    catalog_entry_receiver
                (osid.cataloging.CatalogEntryReceiver): the notification
                callback
        arg:    proxy (osid.proxy.Proxy): a proxy
        return: (osid.cataloging.CatalogEntryNotificationSession) - a
                ``CatalogEntryNotificationSession``
        raise:  NullArgument - ``catalog_entry_receiver`` or ``proxy``
                is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented -
                ``supports_catalog_entryt_notification()`` is ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_catalog_entry_notification()`` is ``true``.*