anchor.diff:            '-v',
             '--release',
             '--no-pub',
  -        ]);
  +        ], environment: <String, String>{
  +          'FLUTTER_WEB': 'true',
  +        });
           await _measureSize('basic_material_app', path.join(sampleDir.path, 'build/web/main.dart.js'), metrics);
         });
       });
  
positive.code:         '-v',
          '--release',
          '--no-pub',
        ]);
        final String output = '${flutterDirectory.path}/examples/flutter_gallery/build/web/main.dart.js';
        await _measureSize('flutter_gallery', output, metrics);
        return null;
  
negative.code:         '-v',
          '--release',
          '--no-pub',
        ], environment: <String, String>{
          'FLUTTER_WEB': 'true',
        });
        final String output = '${flutterDirectory.path}/examples/hello_world/build/web/main.dart.js';
        await _measureSize('hello_world', output, metrics);
        return null;
  