anchor.diff:    final List files;
     final SendPort replyPort;
     final bool verbose;
  -  WorkMessage(this.workerName, this.pkgRoot, this.sdkRoot, this.files, this.replyPort, this.verbose);
  +  WorkMessage(this.workerName, this.pkgRoot, this.sdkRoot, this.files,
  +      this.replyPort, this.verbose);
   }
   
   class ResultMessage {
  
positive.code:     Future out;
      if (env.prettyPrint) {
        out = prettyPrint(globalHitmap, failedLoads, env.output);
      }
      if (env.lcov) {
        out = lcov(globalHitmap, env.output);
      }
  
  
negative.code:   env.lcov = args['lcov'];
    if (args['pretty-print'] && env.lcov) {
      fail('Choose one of pretty-print or lcov output');
    }
    if (!env.lcov) {
      // Use pretty-print either explicitly or by default.
      env.prettyPrint = true;
    }
  