How to use serve-placeholder - 2 common examples

// Graceful 404 error handler
    const { fallback } = this.options.render
    if (fallback) {
      // Dist files
      if (fallback.dist) {
        this.useMiddleware({
          path: this.publicPath,
          handler: servePlaceholder(fallback.dist)
        })
      }

      // Other paths
      if (fallback.static) {
        this.useMiddleware({
          path: '/',
          handler: servePlaceholder(fallback.static)
        })
      }
    }

    // Finally use nuxtMiddleware
    this.useMiddleware(nuxtMiddleware({
      options: this.options,
      nuxt: this.nuxt,
      renderRoute: this.renderRoute.bind(this),
      resources: this.resources
    }))

    // Apply errorMiddleware from modules first
    await this.nuxt.callHook('render:errorMiddleware', this.app)

    // Error middleware for errors that occurred in middleware that declared above

}
    }

    // Add user provided middleware
    for (const m of this.options.serverMiddleware) {
      this.useMiddleware(m)
    }

    // Graceful 404 error handler
    const { fallback } = this.options.render
    if (fallback) {
      // Dist files
      if (fallback.dist) {
        this.useMiddleware({
          path: this.publicPath,
          handler: servePlaceholder(fallback.dist)
        })
      }

      // Other paths
      if (fallback.static) {
        this.useMiddleware({
          path: '/',
          handler: servePlaceholder(fallback.static)
        })
      }
    }

    // Finally use nuxtMiddleware
    this.useMiddleware(nuxtMiddleware({
      options: this.options,
      nuxt: this.nuxt,