this.witnessClient = null;
                        this.witnessEnabled = false;
                    } catch (Exception e) {
                        log.debug("Error closing witness client during emergency cleanup", e);
                    }
                }

                if (this.leaseManager != null) {
                    try {
                        this.leaseManager.shutdown();

    edge-case regression introduced with the events cleanup in 3.14.0.

 *  Fix: Provide actionable advice when the exchange is non-null. Prior to 3.14, OkHttp would
    silently leak connections when an interceptor retries without closing the response body. With
    3.14 we detect this problem but the exception was not helpful.

## Version 3.14.0

_2019-03-14_

                if (ssn.getExpiration() != null && ssn.getExpiration() < now && !ssn.isInUse()) {
                    if (log.isDebugEnabled()) {
                        log.debug("Closing session after timeout " + ssn);
                    }
                    ssn.logoff(false, false);
                }
            }
        }

    }

    @Override
    public void close() {
        if (httpClient == null) {
            return;
        }
        if (logger.isDebugEnabled()) {
            logger.debug("Closing HcHttpClient...");
        }
        if (connectionMonitorTask != null) {
            connectionMonitorTask.cancel();
        }
        if (httpClient != null) {
            try {

	// errors on a previous write(2) operation are reported only on the final close() that releases
	// the open file descriptor.
	//
	// Failing to check the return value when closing a file may lead to silent loss of data.
	// This can especially be observed with NFS and with disk quota.
	return w.Close()
}

       * We eliminate unnecessary node creation by catching cases where old nodes can be reused
       * because their next fields won't change. Statistically, at the default threshold, only
       * about one-sixth of them need cloning when a table doubles. The nodes they replace will be
       * garbage collectable as soon as they are no longer referenced by any reader thread that may
       * be in the midst of traversing table right now.
       */