title: Nodejs async series - pass arguments to next callback
body: <p>When you use async module, how can you then pass arguments from the previous callback to the next?</p>
  
  <p>Here is an example from the docs on github</p>
  
  <pre><code>async.series({
      one: function(callback){
          setTimeout(function(){
              callback(null, 1);
          }, 200);
      },
      two: function(callback){
          setTimeout(function(){
              callback(null, 2);
          }, 100);
      }
  },
  function(err, results) {
      // results is now equal to: {one: 1, two: 2}
  });
  </code></pre>