anchor.diff:     * Return the [Stream] that produces [AnalysisResult]s for added files.
      *
      * Analysis starts when the client starts listening to the stream, and stops
  -   * when the client cancels the subscription.
  +   * when the client cancels the subscription. Note that the stream supports
  +   * only one single subscriber.
      *
      * When the client starts listening, the analysis state transitions to
      * "analyzing" and an analysis result is produced for every added file prior
  
positive.code:     _transitionToAnalyzing();
      _hasWork.notify();
      return completer.future;
    }
  
    /**
  
negative.code:     Object/*=T*/ element = set.first;
      set.remove(element);
      return element;
    }
  }
  
  