code: function serveFile(request, response, path, params) {
    params = normalizeParams(params)
    fs.stat(path, function (err, stat) {
      if (err || !stats.isFile()) {
        response.writeHead(404)
        response.end()
      } else {
        fillObject(params.headers, this.standardHeaders)
        params.headers['content-legth'] = stat.size
        params.headers['content-type'] = mimetypes.getContentTypeFromPath(path)
        response.writeHead(params.httpStatusCode, params.httpStatusMessage, params.headers)
        fs.createReadStream(path, params).pipe(response)
      }
    })
  }
docs: private