serviceCall (mdcliapi session, String service, ZMsg request)
{
ZMsg reply = session.send(service, request);
if (reply != null) {
ZFrame status = reply.pop();
if (status.streq("200")) {
status.destroy();
return reply;
}
else if (status.streq("400")) {
System.out.println("E: client fatal error, aborting");