sender_win.remove(mbr); // causes retransmissions to mbr to stop
for(Map.Entry<Address,AckReceiverWindow> entry: receivers.entrySet()) {
Address member=entry.getKey();
if(!members.contains(member)) {
AckReceiverWindow win=entry.getValue();
win.reset();
}
}
receivers.keySet().retainAll(members);
}
}