async def create_rev_reg(self, rr_id: str, rr_size: int = None) -> None:
        """
        Create revocation registry artifacts and new tails file (with association to
        corresponding revocation registry identifier via symbolic link name)
        for input revocation registry identifier. Symbolic link presence signals completion.
        If revocation registry builder operates in a process external to its Issuer's,
        target directory is hopper directory.

        Raise WalletState for closed wallet.

        :param rr_id: revocation registry identifier
        :param rr_size: revocation registry size (defaults to 64)
        """

        LOGGER.debug('RevRegBuilder.create_rev_reg >>> rr_id: %s, rr_size: %s', rr_id, rr_size)

        if not self.wallet.handle:
            LOGGER.debug('RevRegBuilder.create_rev_reg <!< Wallet %s is closed', self.name)
            raise WalletState('Wallet {} is closed'.format(self.name))

        if not ok_rev_reg_id(rr_id):
            LOGGER.debug('RevRegBuilder.create_rev_reg <!< Bad rev reg id %s', rr_id)
            raise BadIdentifier('Bad rev reg id {}'.format(rr_id))

        rr_size = rr_size or 64

        (cd_id, tag) = rev_reg_id2cred_def_id_tag(rr_id)

        dir_tails = self.dir_tails_top(rr_id)
        dir_target = self.dir_tails_target(rr_id)
        if self.external:
            try:
                makedirs(dir_target, exist_ok=False)
            except FileExistsError:
                LOGGER.warning(
                    'RevRegBuilder.create_rev_reg found dir %s, but task not in progress: rebuilding rev reg %s',
                    dir_target,
                    rr_id)
                rmtree(dir_target)
                makedirs(dir_target, exist_ok=False)

        LOGGER.info('Creating revocation registry (capacity %s) for rev reg id %s', rr_size, rr_id)
        tails_writer_handle = await blob_storage.open_writer(
            'default',
            json.dumps({
                'base_dir': dir_target,
                'uri_pattern': ''
            }))

        (created_rr_id, rr_def_json, rr_ent_json) = await anoncreds.issuer_create_and_store_revoc_reg(
            self.wallet.handle,
            self.did,
            'CL_ACCUM',
            tag,
            cd_id,
            json.dumps({
                'max_cred_num': rr_size,
                'issuance_type': 'ISSUANCE_BY_DEFAULT'
            }),
            tails_writer_handle)

        tails_hash = basename(Tails.unlinked(dir_target).pop())
        with open(join(dir_target, 'rr_def.json'), 'w') as rr_def_fh:
            print(rr_def_json, file=rr_def_fh)
        with open(join(dir_target, 'rr_ent.json'), 'w') as rr_ent_fh:
            print(rr_ent_json, file=rr_ent_fh)
        Tails.associate(dir_tails, created_rr_id, tails_hash)  # associate last: symlink signals completion

        LOGGER.debug('RevRegBuilder.create_rev_reg <<<')