anchor.diff:  
     @protected
     RootTaskContext getContext() {
  -    final bool colorEnabled = _args['color'];
  +    final bool colorEnabled = _args[_colorParam];
       return new RootTaskContext(colorEnabled);
     }
   
  
positive.code:   static ArgParser _getParser() {
      final parser = new ArgParser();
  
      parser.addFlag('color', defaultsTo: true);
  
  
      // TODO: put help in a const
  
negative.code: part of hop;
  
  class Runner {
    static const String _colorParam = 'color';
    static const String RAW_TASK_LIST_CMD = 'print_raw_task_list';
    static final ArgParser _parser = _getParser();
    final ArgResults _args;
  