anchor.diff:    _kOptionTarget,
     _kOptionPackages,
     _kOptionOutput,
  +  _kOptionHeader,
     _kOptionSnapshot,
     _kOptionDepfile,
     _kOptionWorking,
  
positive.code:     ..addOption(_kOptionTarget, help: 'The entry point into the app')
      ..addOption(_kOptionPackages, help: 'The .packages file')
      ..addOption(_kOptionOutput, help: 'The generated flx file')
      ..addOption(_kOptionSnapshot, help: 'The generated snapshot file')
      ..addOption(_kOptionDepfile, help: 'The generated dependency file')
      ..addOption(_kOptionWorking,
  
negative.code: const String _kOptionTarget = 'target';
  const String _kOptionPackages = 'packages';
  const String _kOptionOutput = 'output-file';
  const String _kOptionHeader = 'header';
  const String _kOptionSnapshot = 'snapshot';
  const String _kOptionDepfile = 'depfile';
  const String _kOptionWorking = 'working-dir';
  