code: private void destroyPingExecutor() {
          synchronized (pingExecutor) {
              if (!pingExecutor.isShutdown()) {
                  try {
                      log.debugf("Shutting down WebSocket ping executor");
                      pingExecutor.shutdown();
                      if (!pingExecutor.awaitTermination(1, TimeUnit.SECONDS)) {
                          pingExecutor.shutdownNow();
                      }
                  } catch (Throwable t) {
                      log.warnf("Cannot shut down WebSocket ping executor. Cause=%s", t.toString());
                  }
              }
          }
      }
docs: Call this when you know the feed comm processor object will never be used again
  and thus the ping executor will also never be used again.