Explicit entry. Perform ancestor opening operations,
        then synchronize revocation registry to tails tree content.

        :return: current object

async def open(self) -> 'Issuer':
        """
        Explicit entry. Perform ancestor opening operations,
        then synchronize revocation registry to tails tree content.

        :return: current object
        """

        LOGGER.debug('Issuer.open >>>')

        await super().open()
        for path_rr_id in Tails.links(self._dir_tails, self.did):
            await self._sync_revoc(basename(path_rr_id))

        LOGGER.debug('Issuer.open <<<')
        return self