How to use the @vuepress/shared-utils.fs.remove function in @vuepress/shared-utils

const createClientConfig = require('./webpack/createClientConfig')
  const createServerConfig = require('./webpack/createServerConfig')
  const { createBundleRenderer } = require('vue-server-renderer')
  const { normalizeHeadTag, applyUserWebpackConfig } = require('./util/index')

  logger.wait('\nExtracting site metadata...')
  const options = await prepare(sourceDir, cliOptions, true /* isProd */)
  if (cliOptions.outDir) {
    options.outDir = cliOptions.outDir
  }

  const { outDir } = options
  if (process.cwd() === outDir) {
    return console.error(logger.error(chalk.red('Unexpected option: outDir cannot be set to the current working directory.\n'), false))
  }
  await fs.remove(outDir)
  logger.debug('Dist directory: ' + chalk.gray(require('path').resolve(process.cwd(), outDir)))

  let clientConfig = createClientConfig(options, cliOptions).toConfig()
  let serverConfig = createServerConfig(options, cliOptions).toConfig()

  // apply user config...
  const userConfig = options.siteConfig.configureWebpack
  if (userConfig) {
    clientConfig = applyUserWebpackConfig(userConfig, clientConfig, false)
    serverConfig = applyUserWebpackConfig(userConfig, serverConfig, true)
  }

  // compile!
  const stats = await compile([clientConfig, serverConfig])

  const serverBundle = require(path.resolve(outDir, 'manifest/server.json'))

async function workaroundEmptyStyleChunk () {
    const styleChunk = stats.children[0].assets.find(a => {
      return /styles\.\w{8}\.js$/.test(a.name)
    })
    if (!styleChunk) return
    const styleChunkPath = path.resolve(outDir, styleChunk.name)
    const styleChunkContent = await fs.readFile(styleChunkPath, 'utf-8')
    await fs.remove(styleChunkPath)
    // prepend it to app.js.
    // this is necessary for the webpack runtime to work properly.
    const appChunk = stats.children[0].assets.find(a => {
      return /app\.\w{8}\.js$/.test(a.name)
    })
    const appChunkPath = path.resolve(outDir, appChunk.name)
    const appChunkContent = await fs.readFile(appChunkPath, 'utf-8')
    await fs.writeFile(appChunkPath, styleChunkContent + appChunkContent)
  }
}

async function workaroundEmptyStyleChunk (stats, outDir) {
  const styleChunk = stats.children[0].assets.find(a => {
    return /styles\.\w{8}\.js$/.test(a.name)
  })
  if (!styleChunk) return
  const styleChunkPath = path.resolve(outDir, styleChunk.name)
  const styleChunkContent = await fs.readFile(styleChunkPath, 'utf-8')
  await fs.remove(styleChunkPath)
  // prepend it to app.js.
  // this is necessary for the webpack runtime to work properly.
  const appChunk = stats.children[0].assets.find(a => {
    return /app\.\w{8}\.js$/.test(a.name)
  })
  const appChunkPath = path.resolve(outDir, appChunk.name)
  const appChunkContent = await fs.readFile(appChunkPath, 'utf-8')
  await fs.writeFile(appChunkPath, styleChunkContent + appChunkContent)
}

async function workaroundEmptyStyleChunk () {
    const styleChunk = stats.children[0].assets.find(a => {
      return /styles\.\w{8}\.js$/.test(a.name)
    })
    if (!styleChunk) return
    const styleChunkPath = path.resolve(outDir, styleChunk.name)
    const styleChunkContent = await fs.readFile(styleChunkPath, 'utf-8')
    await fs.remove(styleChunkPath)
    // prepend it to app.js.
    // this is necessary for the webpack runtime to work properly.
    const appChunk = stats.children[0].assets.find(a => {
      return /app\.\w{8}\.js$/.test(a.name)
    })
    const appChunkPath = path.resolve(outDir, appChunk.name)
    const appChunkContent = await fs.readFile(appChunkPath, 'utf-8')
    await fs.writeFile(appChunkPath, styleChunkContent + appChunkContent)
  }
}

async render () {
    // compile!
    const stats = await compile([this.clientConfig, this.serverConfig])
    const serverBundle = require(path.resolve(this.outDir, 'manifest/server.json'))
    const clientManifest = require(path.resolve(this.outDir, 'manifest/client.json'))

    // remove manifests after loading them.
    await fs.remove(path.resolve(this.outDir, 'manifest'))

    // ref: https://github.com/vuejs/vuepress/issues/1367
    if (!this.clientConfig.devtool && (!this.clientConfig.plugins
      || !this.clientConfig.plugins.some(p =>
        p instanceof webpack.SourceMapDevToolPlugin
        || p instanceof webpack.EvalSourceMapDevToolPlugin
      ))) {
      await workaroundEmptyStyleChunk(stats, this.outDir)
    }

    // create server renderer using built manifests
    this.renderer = createBundleRenderer(serverBundle, {
      clientManifest,
      runInNewContext: false,
      inject: false,
      shouldPrefetch: this.context.siteConfig.shouldPrefetch || (() => true),

// apply user config...
  const userConfig = ctx.siteConfig.configureWebpack
  if (userConfig) {
    clientConfig = applyUserWebpackConfig(userConfig, clientConfig, false)
    serverConfig = applyUserWebpackConfig(userConfig, serverConfig, true)
  }

  // compile!
  const stats = await compile([clientConfig, serverConfig])

  const serverBundle = require(path.resolve(outDir, 'manifest/server.json'))
  const clientManifest = require(path.resolve(outDir, 'manifest/client.json'))

  // remove manifests after loading them.
  await fs.remove(path.resolve(outDir, 'manifest'))

  // find and remove empty style chunk caused by
  // https://github.com/webpack-contrib/mini-css-extract-plugin/issues/85
  // TODO remove when it's fixed
  if (!clientConfig.devtool && (!clientConfig.plugins ||           
    !clientConfig.plugins.some(p =>
      p instanceof webpack.SourceMapDevToolPlugin ||
      p instanceof webpack.EvalSourceMapDevToolPlugin
    ))) {
    await workaroundEmptyStyleChunk()
  }

  // create server renderer using built manifests
  const renderer = createBundleRenderer(serverBundle, {
    clientManifest,
    runInNewContext: false,

// apply user config...
  const userConfig = options.siteConfig.configureWebpack
  if (userConfig) {
    clientConfig = applyUserWebpackConfig(userConfig, clientConfig, false)
    serverConfig = applyUserWebpackConfig(userConfig, serverConfig, true)
  }

  // compile!
  const stats = await compile([clientConfig, serverConfig])

  const serverBundle = require(path.resolve(outDir, 'manifest/server.json'))
  const clientManifest = require(path.resolve(outDir, 'manifest/client.json'))

  // remove manifests after loading them.
  await fs.remove(path.resolve(outDir, 'manifest'))

  // find and remove empty style chunk caused by
  // https://github.com/webpack-contrib/mini-css-extract-plugin/issues/85
  // TODO remove when it's fixed
  await workaroundEmptyStyleChunk()

  // create server renderer using built manifests
  const renderer = createBundleRenderer(serverBundle, {
    clientManifest,
    runInNewContext: false,
    inject: false,
    shouldPrefetch: options.siteConfig.shouldPrefetch || (() => true),
    template: await fs.readFile(options.ssrTemplate, 'utf-8')
  })

  // pre-render head tags from user config