title: Node Redis Callback on PubSub
body: <p>Why can't I have a callback with PubSub pattern design in Node Redis?</p>
  
  <p>For instance:</p>
  
  <pre><code>server.publish("someChanel", someData, function(response) {
     // response should come back from client
  });
  
  client.on('message', function(channel, data, callback) {
     // Do stuff with data
     // Return data to callback
     callback(someNewData);
  });
  </code></pre>
  
  <p>This obviously fails as <code>callback</code> is not defined. </p>