anchor.diff:    final options = parser.parse(args);
     if (options["help"]) {
       print("""
  -Usage: compare_results.dart [OPTION]... BEFORE AFTER [APPROVED]
  +Usage: compare_results.dart [OPTION]... BEFORE AFTER
   Compare the old and new test results and list tests that pass the filters.
  -Three-way compare with the approved results if provided.
   All tests are listed if no filters are given.
   
   The options are as follows:
  
positive.code:   // Load the input and the flakiness data if specified.
    final before = await loadResultsMap(parameters[0]);
    final after = await loadResultsMap(parameters[1]);
    final approved = 3 <= parameters.length
        ? await loadResultsMap(parameters[2])
        : <String, Map<String, dynamic>>{};
    final logs = options['logs'] == null
        ? <String, Map<String, dynamic>>{}
        : await loadResultsMap(options['logs']);
  
negative.code:   }
  
    final parameters = options.rest;
    if (parameters.length != 2) {
      print("error: Expected two parameters "
          "(results before, results after)");
      exitCode = 2;
      return;
    }
  