anchor.diff:  
     return content;
   }
  +
  +String createDartAnalysisOptions() {
  +  // TODO(gspencergoog): Update this to Dart "recommended" list once that is finalized.
  +  return '''
  +analyzer:
  +  errors:
  +    # Increase the severity of some hints.
  +    - unused_import: warning
  +
  +linter:
  +  rules:
  +    # Ordering lints.
  +    - directives_ordering
  +    - sort_pub_dependencies
  +
  +    # All other lints.
  +    - always_declare_return_types
  +    - avoid_empty_else
  +    - avoid_relative_lib_imports
  +    - avoid_shadowing_type_parameters
  +    - avoid_types_as_parameter_names
  +    - await_only_futures
  +    - camel_case_extensions
  +    - camel_case_types
  +    - curly_braces_in_flow_control_structures
  +    - empty_catches
  +    - file_names
  +    - hash_and_equals
  +    - iterable_contains_unrelated_type
  +    - list_remove_unrelated_type
  +    - no_duplicate_case_values
  +    - non_constant_identifier_names
  +    - package_prefixed_library_names
  +    - prefer_generic_function_type_aliases
  +    - prefer_is_empty
  +    - prefer_is_not_empty
  +    - prefer_iterable_whereType
  +    - prefer_typing_uninitialized_variables
  +    - provide_deprecation_message
  +    - unawaited_futures
  +    - unnecessary_overrides
  +    - unrelated_type_equality_checks
  +    - valid_regexps
  +    - void_checks
  +''';
  +}
  
positive.code:   joinFile(flutterProjectDir, ['pubspec.yaml'])
        .writeAsStringSync(createPubspec(includeFlutterWeb: true));
    await _runFlutterPubGet(flutterProjectDir);
  }
  
  Future<void> _runDartPubGet(Directory dir) async {
  
negative.code:   joinFile(dartProjectDir, ['pubspec.yaml'])
        .writeAsStringSync(createPubspec(includeFlutterWeb: false));
    await _runDartPubGet(dartProjectDir);
    joinFile(dartProjectDir, ['analysis_options.yaml'])
        .writeAsStringSync(createDartAnalysisOptions());
  
    final flutterProjectPath =
        Directory(path.join(templatesPath.path, 'flutter_project'));
  