if ( log.isDebugEnabled() ) {
                                log.debug("Transport still in use, no idle timeout " + this);
                            }
                            // notify, so that callers with timed-out requests can handle them
                            for ( Response response : this.response_map.values() ) {
                                synchronized ( response ) {

                }
                else if ( last == null ) {
                    // don't have enough credits/space for the first request, block until available
                    // for space there is nothing we can do, callers need to make sure that a single message fits

                    try {
                        long timeout = getResponseTimeout(chain);
                        if ( params.contains(RequestParam.NO_TIMEOUT) ) {