@staticmethod<EOL><INDENT>def current_rev_reg_id(base_dir: str, cd_id: str) -> str:<DEDENT>
tags = [int(rev_reg_id2tag(basename(f))) for f in Tails.links(base_dir)<EOL>if cd_id in basename(f)]<EOL>if not tags:<EOL><INDENT>raise AbsentTails('<STR_LIT>'.format(cd_id))<EOL><DEDENT>return rev_reg_id(cd_id, str(max(tags)))<EOL>
Return the current revocation registry identifier for
input credential definition identifier, in input directory.

Raise AbsentTails if no corresponding tails file, signifying no such revocation registry defined.

:param base_dir: base directory for tails files, thereafter split by cred def id
:param cd_id: credential definition identifier of interest
:return: identifier for current revocation registry on input credential definition identifier