anchor.diff:  
   import 'package:http/http.dart' as http;
   
  -import '../base/common.dart';
   import '../globals.dart';
   import '../runner/flutter_command.dart';
   
  
positive.code:     argParser.addOption('output-file', help: 'Write the Skia picture file to this path.');
      argParser.addOption('skiaserve', help: 'Post the picture to a skiaserve debugger at this URL.');
      argParser.addOption('diagnostic-port',
          defaultsTo: kDefaultDiagnosticPort.toString(),
          help: 'Local port where the diagnostic server is listening.');
    }
  
  
negative.code:       skiaserveUri = Uri.parse(argResults['skiaserve']);
      } else {
        printError('Must provide --output-file or --skiaserve');
        return 1;
      }
      if (argResults['diagnostic-port'] == null) {
        printError('Must provide --diagnostic-port');
        return 1;
      }
  
  