Node.js -- Questions about fields in a POST

I am looking at this Gist (trying my hand at slightly more difficult Node than normal (I know this is still pretty simple :P )): https://gist.github.com/833401

I was wondering why we must specify the

connection.write('?track=' + this.track);

at the end? It has already been established in the request URL. Is this behavior specific to Twitter's API, or is this some sort of Node semantics with POST requests in Node?

Looking forward to your answers!

It's specific to twitter API. You generally don't need to do something like this with normal post requests.