title: How to get NodeJS client id?
body: <p>Running NodeJs I can see a sort of client ID:</p>
  
  <pre><code>debug - emitting heartbeat for client hg5ZurBEi8R3Ehf5kuBJ
  debug - websocket writing 2::
  debug - set heartbeat timeout for client hg5ZurBEi8R3Ehf5kuBJ
  debug - got heartbeat packet
  debug - cleared heartbeat timeout for client hg5ZurBEi8R3Ehf5kuBJ
  debug - set heartbeat interval for client hg5ZurBEi8R3Ehf5kuBJ
  </code></pre>
  
  <p>I am using socket.io. There is a way to get "hg5ZurBEi8R3Ehf5kuBJ"? A sort of app.session_id.</p>