private void serveFile(Request request) {
        request.detach();
        rpcAuthorizer.authorizeFileRequest(request)
                .thenRun(() -> { // okay to do in authorizer thread as serveFile is async
                    FileReference reference = new FileReference(request.parameters().get(0).asString());
                    boolean downloadFromOtherSourceIfNotFound = request.parameters().get(1).asInt32() == 0;
                    var acceptedCompressionTypes = Arrays.stream(request.parameters().get(2).asStringArray())
                            .map(CompressionType::valueOf)
                            .collect(Collectors.toSet());
                    var receiver = new ChunkedFileReceiver(request.target());
                    fileServer.serveFile(reference, downloadFromOtherSourceIfNotFound, acceptedCompressionTypes, request, receiver);
                });
    }
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