if ( retries != 1 ) {
                    // backoff, but don't delay the first attempt as there are various reasons that can be fixed
                    // immediately
                    Thread.sleep(500 + RAND.nextInt(1000));
                }
            }
            catch ( InterruptedException e ) {
                log.debug("interrupted sleep in send", e);
            }

            if ( request != null ) {

    static final void randBytes ( Random r, byte[] buffer ) {
        // regular nextBytes is not reproducible if the reads are not aligned
        for ( int i = 0; i < buffer.length; i++ ) {
            buffer[ i ] = (byte) r.nextInt(256);
        }

    }