code: void refreshSession(boolean forceRefresh) throws AzkabanClientException {
      Preconditions.checkArgument(this.sessionCreationTime != 0);
      boolean expired = (System.nanoTime() - this.sessionCreationTime) > Duration
          .ofMinutes(this.sessionExpireInMin)
          .toNanos();
  
      if (expired) {
        log.info("Session expired. Generating a new session.");
      } else if (forceRefresh) {
        log.info("Force to refresh session. Generating a new session.");
      }
  
      if (expired || forceRefresh) {
        this.sessionId = this.sessionManager.fetchSession();
        this.sessionCreationTime = System.nanoTime();
      }
    }
docs: When current session expired, use {@link SessionManager} to refresh the session id.