anchor.diff:  
     /**
      * Sends an Event hit to Google Analytics. [category] specifies the event
  -   * category. [action] specifies the event action/ [value] specifies the event
  -   * value; values must be non-negative.
  +   * category. [action] specifies the event action, [label] specifies the event
  +   * label, and [value] specifies the event value. Values must be non-negative.
      */
     void sendEvent(String category, String action, [String label, String value]) {
       _proxy.callMethod('sendEvent', [category, action, label, value]);
  
positive.code:    * Sends an Exception hit to Google Analytics. [description] is the exception
     * description (up to 100 chars), and [fatal] indicates whether the exception
     * was fatal.
     */
    void sendException([String description, bool fatal]) {
      _proxy.callMethod('sendException', [description, fatal]);
  
negative.code: /**
   * A library to use Google Analytics with Chrome Apps. This is a wrapper around
   * the
   * [chrome-platform-analytics](https://github.com/GoogleChrome/chrome-platform-analytics).
   * JavaScript library.
   *
   * Example use:
  