anchor.diff:      await serverConnection.sendAddOverlay(src);
       await serverConnection.analysisComplete.first;
       var fixes = await serverConnection.sendGetFixes(offset);
  -    serverConnection.sendRemoveOverlay();
  +    await serverConnection.sendRemoveOverlay();
       return fixes;
     }
   
  
positive.code:     isSetup = true;
  
      _logger.fine("Setup done");
  
      return analysisComplete.first;
    }
  
  
negative.code:    * [DUMP_SERVER_MESSAGES] is true.
     */
    void _logStdio(String line) {
      if (dumpServerMessages)
        print(line);
    }
  }
  