@Override
        public void receive(FileReferenceData fileData, FileServer.ReplayStatus status) {
            int session = sendMeta(fileData);
            sendParts(session, fileData);
            sendEof(session, fileData, status);
        }
Returns true if empty sentinel config can be returned when a request from a host that is
not part of an application asks for sentinel config
configserver/src/main/java/com/yahoo/vespa/config/server/rpc/RpcServer.java