anchor.diff:      var output = await inlineImagesWithIncludeDirs(
           input, opts.includeDirs.map((path) => new Directory(path)).toList());
       if (output != null) {
  +      final cssJanusPath =
  +          opts.cssjanusPath?.path ?? pathResolver.defaultCssJanusPath;
  +      if (opts.cssjanusDirection == 'rtl') {
  +        final inlined = await output.readAsString();
  +        final flipped = await runCssJanus(inlined, cssJanusPath);
  +        output = new Asset.fromString(output.id, flipped);
  +      } else if (opts.cssjanusDirection == 'bidi') {
  +        final inlined = await output.readAsString();
  +        final bidirectionalized =
  +        await bidirectionalizeCss(inlined, (String css) async {
  +          return runCssJanus(css, cssJanusPath);
  +        });
  +        output = new Asset.fromString(output.id, bidirectionalized);
  +      }
         result = await _pipeResult(output, opts.outputFile, result.stderr);
       }
     }
  
positive.code: import 'package:barback/barback.dart' show Asset;
  import 'package:quiver/check.dart';
  
  import '../image_inlining/main.dart';
  import '../utils/io_utils.dart';
  import '../utils/path_resolver.dart';
  
negative.code:     ..addFlag('version', abbr: 'v')
      ..addFlag('sourcemap', abbr: 'm')
      ..addOption('cssjanus-path')
      ..addOption('cssjanus-direction', allowed: ['ltr', 'rtl', 'bidi'])
      ..addOption('load-path', abbr: 'I', allowMultiple: true)
      ..addOption('plugin-path', abbr: 'P')
      ..addOption('precision', abbr: 'p')
  