Documentation for response error handling outdated?

According to the docs, when there is an error (eg. 404), I have to obtain the error using "err.status".
http://visionmedia.github.io/superagent/#error-handling

```
if (err && err.status === 404) {
alert('oh no ' + res.body.message);
}
```

However, when I tried to make a 404 error, "err" only shows a text-based message, doesn't seem like an object.

Here is what I get from console.log()

```
Error: Not Found
at Request. (http://localhost/codebase/assets/portal/js/vendor.js:76987:19)
at Request.Emitter.emit (http://localhost/codebase/assets/portal/js/vendor.js:5623:20)
at XMLHttpRequest.xhr.onreadystatechange (http://localhost/codebase/assets/portal/js/vendor.js:77258:10)
```

I know I can get that status information in "res", but the above is not the purpose my current task. It is though a factor I must consider before I decide on my approach. I would like to understand how it functions completely (including border line cases) before I start writing my code. I found that it doesn't quite work like the documentation suggests.
#

This also doesn't work as documented I think. The 404 error doesn't seem to come into here, though it does trigger "end()" callback method:

```
.on('error', function(err) {
console.log('Error: ', res, err);
})
```
#

May I ask if the doc is outdated or something? Or if I completely misunderstood, please do let me know.

Your help is appreciated. Thanks!

Cheers,
Thomas