anchor.diff:  
                  if (task == null) {
                    log.info("Got null next ready task, sleeping");
  -                 await new Future.delayed(new Duration(seconds: 5));
  +                 await new Future.delayed(DELAY_BETWEEN_TASK_POLLS);
                    continue;
                  }
   
  
positive.code: 
  String workerFolder;
  const START_NAME = "worker_isolate.dart";
  
  // Worker properties.
  SendPort sendPort;
  
negative.code: 
      gae_utils.CloudStorageLocation sourceLocation = await task.sourceLocation;
      if (lastSeenMd5 != null && sourceLocation.md5 == lastSeenMd5) {
        log.trace("Source JSON cache hit: $lastSeenMd5");
        if (cachedSourceJSON == null) {
          throw "Invariant check failed: Cached key matched but source was null";
        }
  
        sourceJSON = cachedSourceJSON;
      } else {
        var oldMd5 = lastSeenMd5;
  
        sourceJSON = await
          gae_utils.CloudStorage.getFileContentsByLocation(sourceLocation)
              .transform(UTF8.decoder).join();
          lastSeenMd5 = sourceLocation.md5;
          cachedSourceJSON = sourceJSON;
          log.trace("Cache miss (was: $oldMd5): Source JSON acquired $lastSeenMd5");
      }
  
      var sourceMap = JSON.decode(sourceJSON);
  