How james.js error handling should be done?

james.js

// james-coffee/index.js
var james  = require('james'),
    coffee = require('coffee-script');

coffee.createStream = function() {
  return james.createTransformation(function(content, callback) {

    // Process the file content and call the callback with the result.
    try {
      res = coffee.compile(content);
      callback(null, res);
    } catch(err) {
      callback(err, null);
    }
  });
};

james.read('./hello.coffee')
  .transform(coffee.createStream)
  .write(process.stdout);