static Request createMetaRequest(FileReferenceData fileData) {
            Request request = new Request(FileReceiver.RECEIVE_META_METHOD);
            request.parameters().add(new StringValue(fileData.fileReference().value()));
            request.parameters().add(new StringValue(fileData.filename()));
            request.parameters().add(new StringValue(fileData.type().name()));
            request.parameters().add(new Int64Value(fileData.size()));
            request.parameters().add(new StringValue(fileData.compressionType().name()));
            return request;
        }
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