title: How to actually separate access log from error log in Node.js Express?
body: <p>I've seen this question:
  <a href="https://stackoverflow.com/questions/5489815/logging-in-express-js-to-a-output-file">Logging in express js to a output file?</a></p>
  
  <p>But after reading documentation on <code>logger</code> middleware, still not sure how you can actually separate access log from error log, so that access log contains only url access data, and error log contains only errors.</p>
  
  <p>Is there a way to do that?</p>