title: Writable stream finished?
body: <p>I'm trying to implement a writable stream in Node.js. I was reading through SubStack's <a href="https://github.com/substack/stream-handbook#creating-a-writable-stream" rel="nofollow">excellent stream handbook</a>. I was wondering whether there's a way to find out inside the writable stream when the read stream has stopped writing (when it calls <em>push(null)</em>)? Is it OK for the implementation of a writable stream to subscribe to the <em>finish</em> event?</p>