docs: private void checkTimeout() {
          if (timerMDC != null) {
              MDC.put("name", timerMDC);
          }
          if (docBuffer.isEmpty()) {
              return;
          }
  
          // How long has the NEWest item been waiting?
          long wait = ((new Date().getTime()) - bufferYoungest) / 1000;
          // If the buffer has been updated in the last 20s ignore it
          if (wait < 20) {
              return;
          }
  
          // Else, time to flush the buffer
          log.debug("=== Flushing old buffer: {}s", wait);
          submitBuffer(true);
      }