How to use the @theia/application-package.NpmRegistry function in @theia/application-package

constructor(
        @inject(ApplicationProjectOptions) readonly options: ApplicationProjectOptions,
        @inject(FileSystemWatcherServer) protected readonly fileSystemWatcher: FileSystemWatcherServer,
        @inject(ILogger) protected readonly logger: ILogger,
        @inject(NpmClient) protected readonly npmClient: NpmClient,
    ) {
        logger.debug('AppProjectOptions', options);
        this.registry = new NpmRegistry({
            watchChanges: this.options.watchRegistry
        });
        this.backup();
        this.packageUri = FileUri.create(this.packagePath).toString();
        this.toDispose.push(this.fileSystemWatcher);
        this.fileSystemWatcher.setClient({
            onDidFilesChanged: changes => this.onDidFilesChanged(changes)
        });
        this.fileSystemWatcher.watchFileChanges(this.packageUri).then(watcher =>
            this.toDispose.push(Disposable.create(() =>
                this.fileSystemWatcher.unwatchFileChanges(watcher)
            ))
        );
        this.toDispose.push(this.onWillInstallEmitter);
        this.toDispose.push(this.onDidInstallEmitter);
    }