docs: async def get_box_ids_issued(self) -> str:
          """
          Return json object on lists of all unique box identifiers (schema identifiers,
          credential definition identifiers, and revocation registry identifiers) for
          all credential definitions and credentials issued; e.g.,
  
          ::
  
              {
                  "schema_id": [
                      "R17v42T4pk...:2:tombstone:1.2",
                      ...
                  ],
                  "cred_def_id": [
                      "R17v42T4pk...:3:CL:19:tag",
                      ...
                  ]
                  "rev_reg_id": [
                      "R17v42T4pk...:4:R17v42T4pk...:3:CL:19:tag:CL_ACCUM:0",
                      "R17v42T4pk...:4:R17v42T4pk...:3:CL:19:tag:CL_ACCUM:1",
                      ...
                  ]
              }
  
          An issuer must issue a credential definition to include its schema identifier
          in the returned values; the schema identifier in isolation belongs properly
          to an Origin, not necessarily to an Issuer.
  
          The operation may be useful for a Verifier anchor going off-line to seed its
          cache before doing so.
  
          :return: tuple of sets for schema ids, cred def ids, rev reg ids
          """
  
          LOGGER.debug('Issuer.get_box_ids_issued >>>')
  
          cd_ids = [
              d for d in listdir(self.dir_tails) if isdir(join(self.dir_tails, d)) and ok_cred_def_id(d, self.did)]
          s_ids = []
          for cd_id in cd_ids:
              try:
                  s_ids.append(json.loads(await self.get_schema(cred_def_id2seq_no(cd_id)))['id'])
              except AbsentSchema:
                  LOGGER.error(
                      'Issuer %s has issued cred def %s but no corresponding schema on ledger',
                      self.name,
                      cd_id)
          rr_ids = [basename(link) for link in Tails.links(self.dir_tails, self.did)]
  
          rv = json.dumps({
              'schema_id': s_ids,
              'cred_def_id': cd_ids,
              'rev_reg_id': rr_ids
          })
          LOGGER.debug('Issuer.get_box_ids_issued <<< %s', rv)
          return rv