anchor.diff:  
     Future run(Resource resource) {
       Container launchContainer = getAppContainerFor(resource);
  -    return updateManifest(launchContainer.entry).then((_) {
  +    return updateManifest(launchContainer.entry).then((String id) {
         return developerPrivate.loadDirectory(launchContainer.entry).then(
             (String appId) {
           // TODO: Use the returned appId once it has the correct results.
  
positive.code:           String key = manifestDict['key'];
            if (id == SPARK_NIGHTLY_ID && key == SPARK_NIGHTLY_KEY) {
              manifestDict['key'] = SPARK_RELEASE_KEY;
            } else if (id == SPARK_RELEASE_ID && key == SPARK_RELEASE_KEY) {
              manifestDict['key'] = SPARK_NIGHTLY_KEY;
            } else {
              return new Future.value();
            }
            // This modifies the manifest file permanently.
            return entry.writeText(new JsonPrinter().print(manifestDict));
          });
        });
      } else {
  
negative.code:         // TODO: Delay a bit - there's a race condition.
          return new Future.delayed(new Duration(milliseconds: 100));
        }).then((_) {
          if (id != null) {
            return launchId(id);
          } else {
             return _getAppId(launchContainer.name).then((String id)
                 => launchId(id));
          }
        });
      });
    }
  
    /**
    * Launches a chrome app with given [id].
    */
    Future launchId(String id) {
      if (id == null) {
        throw 'Unable to locate an application id.';
      } else if (!management.available) {
        throw 'The chrome.management API is not available.';
      } else {
        return management.launchApp(id);
      }
    }
  
    /**
  