title: Define koa-router nested routes w/ prefixes
body: <p>I'm trying to define different routes using <code>koa-router</code> and I'm having a hellova time getting it working.</p>
  
  <p>Something like this:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>const apiRouter = new KoaRouter({
    prefix: '/api'
  })
  .use(bodyParser)
  .post('/sign-in', signinMiddleware)
  .get('auth-check', authCheckMiddleware)
  
  const protectedApisRouter = new KoaRouter()
  .use(authorizeMiddleware)
  .get('/widgets', getWidgetsListMiddleware)
  .post('/widgets', createWidgetMiddleware)
  .get('/widgets/:widgetId', getWidgetByIdMiddleware)
  .patch('/widgets/:widgetId', updateWidgetMiddleware)
  
  
  apiRouter.use(
    prodectedApisRouter.routes(),
    prodectedApisRouter.allowedMethods()
  )
  
  koaApp.use(apiRouter.routes())
  koaApp.use(apiRouter.allowedMethods())
   </code></pre>
  </div>
  </div>
  </p>
  
  <p>I would expect that an requests to <code>/api/widgets/*</code> SHOULD enter into their respective middleware, after the <code>bodyParser</code> and <code>authorizeMiddleware</code> middleware` run, based on the documentation here: <a href="https://github.com/alexmingoia/koa-router#nested-routers" rel="nofollow noreferrer">https://github.com/alexmingoia/koa-router#nested-routers</a></p>
  
  <p>But instead, I'm getting 404's for all of those routes.  What am I doing wrong?    </p>