anchor.diff:                      '--include-lib', 'spark.server,spark.tcp',
                       '--include-lib', 'git,git.objects,git.zlib',
                       'app/spark.dart']);
  -
  -    if (Platform.isWindows) {
  -      try {
  -        // 7z a -r ..\dist\spark-docs.zip .
  -        runProcess(
  -            context,
  -            '7z',
  -            arguments: ['a', '-r', '../${DIST_DIR.path}/spark-docs.zip', '.'],
  -            workingDirectory: 'docs',
  -            quiet: true);
  -      } on ProcessException catch(e) {
  -        context.fail("Unable to execute 7z.\n"
  -          "Please install 7zip. Add 7z directory to the PATH environment variable.");
  -      };
  -    } else {
  -      // zip spark-docs.zip . -r -q -x .*
  -      runProcess(
  -          context,
  -          'zip',
  -          arguments: ['../${DIST_DIR.path}/spark-docs.zip', '.', '-qr', '-x', '.*'],
  -          workingDirectory: 'docs');
  -    }
  +    _zip(context, 'docs', '../${DIST_DIR.path}/spark-docs.zip');
     }
   }
   
  
positive.code: // - Remove test
  // - Zip the content of build/chrome-app-spark to dist/spark.zip
  void archive(GrinderContext context) {
    if (Platform.isWindows) {
      _delete('dist/spark.zip');
  
      try {
        // 7z a -r ..\dist\spark.zip .
        runProcess(
            context,
            '7z',
            arguments: ['a', '-r', '../${DIST_DIR.path}/spark.zip', '.'],
            workingDirectory: 'app',
            quiet: true);
      } on ProcessException catch(e) {
        context.fail("Unable to execute 7z.\n"
          "Please install 7zip. Add 7z directory to the PATH environment variable.");
      };
    } else {
      // zip spark.zip . -r -q -x .*
      runProcess(
          context,
          'zip',
          arguments: ['../${DIST_DIR.path}/spark.zip', '.', '-qr', '-x', '.*'],
          workingDirectory: 'app');
    }
  
    _printSize(context, getFile('dist/spark.zip'));
  }
  
  void docs(GrinderContext context) {
  
negative.code:   }
  }
  
  // TODO(sunglim): Fix me. This doesn't support Windows.
  String _getCommandOutput(String command) {
    return Process.runSync('/bin/sh', ['-c', command]).stdout.trim();
  }
  