How to use the @jupyterlab/application.JupyterFrontEnd.IPaths function in @jupyterlab/application

id: 'jupyter.extensions.hub-extension',
  requires: [JupyterFrontEnd.IPaths, ICommandPalette, IMainMenu],
  autoStart: true
};

/**
 * The default JupyterLab connection lost provider. This may be overridden
 * to provide custom behavior when a connection to the server is lost.
 *
 * If the application is being deployed within a JupyterHub context,
 * this will provide a dialog that prompts the user to restart the server.
 * Otherwise, it shows an error dialog.
 */
const connectionlost: JupyterFrontEndPlugin = {
  id: '@jupyterlab/apputils-extension:connectionlost',
  requires: [JupyterFrontEnd.IPaths],
  activate: (
    app: JupyterFrontEnd,
    paths: JupyterFrontEnd.IPaths
  ): IConnectionLost => {
    const hubPrefix = paths.urls.hubPrefix || '';
    const baseUrl = paths.urls.base;

    // Return the default error message if not running on JupyterHub.
    if (!hubPrefix) {
      return ConnectionLost;
    }

    // If we are running on JupyterHub, return a dialog
    // that prompts the user to restart their server.
    let showingError = false;
    const onConnectionLost: IConnectionLost = async (

activate: async (app: JupyterFrontEnd): Promise => {
    const connector = app.serviceManager.settings;
    const plugins = (await connector.list()).values;

    return new SettingRegistry({ connector, plugins });
  },
  autoStart: true,
  provides: ISettingRegistry
};

/**
 * The default theme manager provider.
 */
const themes: JupyterFrontEndPlugin = {
  id: '@jupyterlab/apputils-extension:themes',
  requires: [ISettingRegistry, JupyterFrontEnd.IPaths],
  optional: [ISplashScreen],
  activate: (
    app: JupyterFrontEnd,
    settings: ISettingRegistry,
    paths: JupyterFrontEnd.IPaths,
    splash: ISplashScreen | null
  ): IThemeManager => {
    const host = app.shell;
    const commands = app.commands;
    const url = URLExt.join(paths.urls.base, paths.urls.themes);
    const key = themes.id;
    const manager = new ThemeManager({ key, host, settings, splash, url });

    // Keep a synchronously set reference to the current theme,
    // since the asynchronous setting of the theme in `changeTheme`
    // can lead to an incorrect toggle on the currently used theme.

namespace CommandIDs {
  export const changeTheme = 'apputils:change-theme';

  export const themeScrollbars = 'apputils:theme-scrollbars';

  export const incrFontSize = 'apputils:incr-font-size';

  export const decrFontSize = 'apputils:decr-font-size';
}

/**
 * The default theme manager provider.
 */
export const themesPlugin: JupyterFrontEndPlugin = {
  id: '@jupyterlab/apputils-extension:themes',
  requires: [ISettingRegistry, JupyterFrontEnd.IPaths],
  optional: [ISplashScreen],
  activate: (
    app: JupyterFrontEnd,
    settings: ISettingRegistry,
    paths: JupyterFrontEnd.IPaths,
    splash: ISplashScreen | null
  ): IThemeManager => {
    const host = app.shell;
    const commands = app.commands;
    const url = URLExt.join(paths.urls.base, paths.urls.themes);
    const key = themesPlugin.id;
    const manager = new ThemeManager({ key, host, settings, splash, url });

    // Keep a synchronously set reference to the current theme,
    // since the asynchronous setting of the theme in `changeTheme`
    // can lead to an incorrect toggle on the currently used theme.

restorer.save(labShell.saveLayout());
      });
    });

    return restorer;
  },
  autoStart: true,
  provides: ILayoutRestorer
};

/**
 * The default URL router provider.
 */
const router: JupyterFrontEndPlugin = {
  id: '@jupyterlab/application-extension:router',
  requires: [JupyterFrontEnd.IPaths],
  activate: (app: JupyterFrontEnd, paths: JupyterFrontEnd.IPaths) => {
    const { commands } = app;
    const base = paths.urls.base;
    const router = new Router({ base, commands });

    app.started.then(() => {
      // Route the very first request on load.
      router.route();

      // Route all pop state events.
      window.addEventListener('popstate', () => {
        router.route();
      });
    });

    return router;

console.warn('Tree routing failed.', error);
        }
      }
    });

    router.register({ command: CommandIDs.tree, pattern: treePattern });
    router.register({ command: CommandIDs.tree, pattern: workspacePattern });
  }
};

/**
 * The default URL not found extension.
 */
const notfound: JupyterFrontEndPlugin = {
  id: '@jupyterlab/application-extension:notfound',
  requires: [JupyterFrontEnd.IPaths, IRouter],
  activate: (
    _: JupyterFrontEnd,
    paths: JupyterFrontEnd.IPaths,
    router: IRouter
  ) => {
    const bad = paths.urls.notFound;

    if (!bad) {
      return;
    }

    const base = router.base;
    const message = `
      The path: ${bad} was not found. JupyterLab redirected to: ${base}
    `;

provides: JupyterLab.IInfo
};

/**
 * The default JupyterLab paths dictionary provider.
 */
const paths: JupyterFrontEndPlugin = {
  id: '@jupyterlab/apputils-extension:paths',
  activate: (app: JupyterFrontEnd): JupyterFrontEnd.IPaths => {
    if (!(app instanceof JupyterLab)) {
      throw new Error(`${paths.id} must be activated in JupyterLab.`);
    }
    return app.paths;
  },
  autoStart: true,
  provides: JupyterFrontEnd.IPaths
};

/**
 * Export the plugins as default.
 */
const plugins: JupyterFrontEndPlugin[] = [
  main,
  layout,
  router,
  tree,
  notfound,
  busy,
  sidebar,
  shell,
  status,
  info,

if (printFunction) {
          await printFunction();
        }
      }
    });
  }
};

/**
 * The default state database for storing application state.
 */
const state: JupyterFrontEndPlugin = {
  id: '@jupyterlab/apputils-extension:state',
  autoStart: true,
  provides: IStateDB,
  requires: [JupyterFrontEnd.IPaths, IRouter, IWindowResolver],
  optional: [ISplashScreen],
  activate: (
    app: JupyterFrontEnd,
    paths: JupyterFrontEnd.IPaths,
    router: IRouter,
    resolver: IWindowResolver,
    splash: ISplashScreen | null
  ) => {
    let debouncer: number;
    let resolved = false;

    const { commands, serviceManager } = app;
    const { workspaces } = serviceManager;
    const workspace = resolver.name;
    const transform = new PromiseDelegate();
    const db = new StateDB({