Benchmarking in node.js?

I want to see how long it takes for a line of code to execute in node.js. Speicifiaclly, I want to know how long it takes socket.io to get data that is attached to a socket.

So I do socket.set 'user_id', user_id. Then to get the data back I do:

#clock start
socket.get "screen_id", (err, screen_id)->
  #clock stop
  ...

Is there a good way to measure how long this takes? I want to compare this with another way to implementing the feature.