code: func FSHandler(root string, stripSlashes int) RequestHandler {
  	fs := &FS{
  		Root:               root,
  		IndexNames:         []string{"index.html"},
  		GenerateIndexPages: true,
  		AcceptByteRange:    true,
  	}
  	if stripSlashes > 0 {
  		fs.PathRewrite = NewPathSlashesStripper(stripSlashes)
  	}
  	return fs.NewRequestHandler()
  }
docs: // FSHandler returns request handler serving static files from
  // the given root folder.
  //
  // stripSlashes indicates how many leading slashes must be stripped
  // from requested path before searching requested file in the root folder.
  // Examples:
  //
  //   * stripSlashes = 0, original path: "/foo/bar", result: "/foo/bar"
  //   * stripSlashes = 1, original path: "/foo/bar", result: "/bar"
  //   * stripSlashes = 2, original path: "/foo/bar", result: ""
  //
  // The returned request handler automatically generates index pages
  // for directories without index.html.
  //
  // The returned handler caches requested file handles
  // for FSHandlerCacheDuration.
  // Make sure your program has enough 'max open files' limit aka
  // 'ulimit -n' if root folder contains many files.
  //
  // Do not create multiple request handler instances for the same
  // (root, stripSlashes) arguments - just reuse a single instance.
  // Otherwise goroutine leak will occur.