anchor.diff:        .split(" ")
         .last;
   }
  +
  +/// Print the usage information for Sass, with [message] as a header.
  +void _printUsage(ArgParser parser, String message) {
  +  print("$message\n");
  +  print("Usage: dart-sass <input>\n");
  +  print(parser.usage);
  +}
  
positive.code:   }
  
    if (options['help'] as bool || options.rest.isEmpty) {
      print("Compile Sass to CSS.\n");
      print("Usage: dart-sass <input>\n");
      print(argParser.usage);
      exitCode = 64;
      return;
    }
  
negative.code:         abbr: 'h', help: 'Print this usage information.', negatable: false)
      ..addFlag('version',
          help: 'Print the version of Dart Sass.', negatable: false);
  
    ArgResults options;
    try {
      options = argParser.parse(args);
    } on FormatException catch (error) {
      _printUsage(argParser, error.message);
      exitCode = 64;
      return;
    }
  
    if (options['version'] as bool) {
      _loadVersion().then((version) {
  