code: protected Single<Boolean> isValidClientCredentials(String clientId, String clientSecret) {
          return db.findClientCredentials(clientId)
                  .map(creds -> creds.getSecret().equals(clientSecret))
                  .switchIfEmpty(Single.just(false))
                  ;
      }
docs: check only that LOCAL_NODE_ID and clientSecret are valid, NOT that the status is active