supportedInternalAddonPaths() {
    if (!this.root) {
      return [];
    }

    let internalMiddlewarePath = path.join(__dirname, '../tasks/server/middleware');
    let internalTransformPath = path.join(__dirname, '../tasks/transforms');

    return [
      path.join(internalMiddlewarePath, 'testem-url-rewriter'),
      path.join(internalMiddlewarePath, 'tests-server'),
      path.join(internalMiddlewarePath, 'history-support'),
      path.join(internalMiddlewarePath, 'broccoli-watcher'),
      path.join(internalMiddlewarePath, 'broccoli-serve-files'),
      path.join(internalMiddlewarePath, 'proxy-server'),
      path.join(internalTransformPath, 'amd'),
    ];
  }
Provides the list of paths to consult for addons that may be provided
    internally to this project. Used for middleware addons with built-in support.

    @private
    @method supportedInternalAddonPaths