How to use the apollo-language-server.GraphQLServiceProject function in apollo-language-server

// When no config is provided, configURI === process.cwd()
    // In this case, we don't want to look to the .dir since that's the parent
    const configPath = config.configURI!.fsPath;
    const rootURI =
      configPath === process.cwd()
        ? URI.file(configPath)
        : URI.file(parse(configPath).dir);

    const clientIdentity = {
      name: "Apollo CLI",
      version,
      referenceID
    };

    if (isServiceConfig(config)) {
      this.project = new GraphQLServiceProject({
        config,
        loadingHandler,
        rootURI,
        clientIdentity
      });
    } else if (isClientConfig(config)) {
      this.project = new GraphQLClientProject({
        config,
        loadingHandler,
        rootURI,
        clientIdentity
      });
    } else {
      throw new Error(
        "Unable to resolve project type. Please add either a client or service config. For more information, please refer to https://bit.ly/2ByILPj"
      );