sender=random_member;
dest=random_member;
    public void retransmit(long first_seqno, long last_seqno, Address sender) {        NakAckHeader hdr;        Message retransmit_msg;        if(xmit_from_random_member && !local_addr.equals(sender)) {            Address random_member=(Address)Util.pickRandomElement(members);            if(random_member != null && !local_addr.equals(random_member)) {                sender=random_member;                if(log.isTraceEnabled())                    log.trace("picked random member " + random_member + " to send XMIT request to");            }        }        retransmit_msg=new Message(sender, null, null);        if(log.isTraceEnabled())            log.trace(local_addr + ": sending XMIT_REQ ([" + first_seqno + ", " + last_seqno + "]) to " + sender);        hdr=new NakAckHeader(NakAckHeader.XMIT_REQ, first_seqno, last_seqno, sender);        retransmit_msg.putHeader(name, hdr);        passDown(new Event(Event.MSG, retransmit_msg));    }