code: public synchronized void start() {
      if (mStopped) {
        Preconditions.checkState(mLoggingWorkerThread == null);
        mStopped = false;
        mLoggingWorkerThread = new Thread(new AuditLoggingWorker());
        mLoggingWorkerThread.setName(AUDIT_LOG_THREAD_NAME);
        mLoggingWorkerThread.start();
        LOG.info("AsyncUserAccessAuditLogWriter thread started.");
      }
    }
docs: Starts {@link AsyncUserAccessAuditLogWriter}.