TodoStore.js

var TodoStore = assign({}, EventEmitter.prototype, {
  /*
   * These aren't really necessary:
   *
  addChangeListener: function(callback) {
    this.on(CHANGE_EVENT, callback);
  },
  removeChangeListener: function(callback) {
    this.removeListener(CHANGE_EVENT, callback);
  }
  */
  emitChange: function() {
    // Instead of having the change string on a local constant, 
    // you can place on your app's constants module.
    // this.emit(CHANGE_EVENT);
    this.emit(StoreConstants.CHANGE);
  },
});

module.exports = TodoStore;