docs: public static String closeAllAndShutdown(String logDir, long timeOutMillis) throws IOException {
          String path = null;
          final VoltTrace tracer = s_tracer;
  
          if (tracer != null) {
              if (logDir != null) {
                  path = dump(logDir);
              }
  
              s_tracer = null;
  
              if (timeOutMillis >= 0) {
                  try {
                      tracer.m_writerThread.shutdownNow();
                      tracer.m_writerThread.awaitTermination(timeOutMillis, TimeUnit.MILLISECONDS);
                  } catch (InterruptedException e) {
                  }
              }
  
              tracer.shutdown();
          }
  
          return path;
      }