code: def cred_def_id(self, issuer_did: str, schema_seq_no: int) -> str:
          
  
          return '{}:3:CL:{}{}'.format(  # 3 marks indy cred def id, CL is sig type
              issuer_did,
              schema_seq_no,
              self.cd_id_tag(True))
docs: Return credential definition identifier for input issuer DID and schema sequence number.
  
          :param issuer_did: DID of credential definition issuer
          :param schema_seq_no: schema sequence number
          :return: credential definition identifier