@staticmethod<EOL><INDENT>def links(base_dir: str, issuer_did: str = None) -> set:<DEDENT>
return {join(dp, f) for dp, dn, fn in walk(base_dir) for f in fn<EOL>if islink(join(dp, f)) and (not issuer_did or f.startswith('<STR_LIT>'.format(issuer_did)))}<EOL>
Return set of all paths to symbolic links (rev reg ids) associating
their respective tails files, in specified base tails directory, on
input issuer DID if specified.

:param base_dir: base directory for tails files, thereafter split by cred def id
:param issuer_did: issuer DID of interest
:return: set of paths to symbolic links associating tails files