ExpressJoiSwagger.wrapRouter wrapped express app doesn't return http.Server

[cmmash]

Say I initialize my swagger instance in a swaggers.js module as:

const swagger = new ExpressJoiSwagger({
  swaggerDefinition: {},
  ...
module.exports = swagger;

And then in my server file:

const swagger = require('./utils/swagger');
const app = express();

swaggerizedApp = swagger.wrapRouter(app);
const httpServer = swaggerizedApp.listen(SERVER_PORT, () => {
   console.log('swagger joi enabled server listening on ...');
});

But httpServer is undefined. I need it to pass it on to a Socket.IO server.
Is this a bug or am I doing something wrong?

Edit: Yup, found the issue: https://github.com/richardgirges/express-joi-swagger/blob/master/src/index.js#L129

  /**
   * Initiate express app.listen() and build the master swagger definition
   * @param {Object} expressRouter
   * @param {...any} args
   */
  _listen(expressRouter, ...args) {
    this._buildSwaggerDefinition(expressRouter);

    expressRouter.listen(...args); /* <<<<<<< PROBLEM */
  }

the express router listen call result isn't returned.