anchor.diff:    /// that need to be documented.  See [Feature] for a list.
     Set<Feature> get features {
       return {
  -      ...annotations.where((a) => !_specialFeatures.contains(a.name)),
  +      ...annotations.whereNot((a) => _specialFeatures.contains(a.name)),
         // 'const' and 'static' are not needed here because 'const' and 'static'
         // elements get their own sections in the doc.
         if (isFinal) Feature.finalFeature,
  
positive.code:       DartdocOptionContext.fromContextElement(
            packageGraph.config, library!.element, packageGraph.resourceProvider);
  
    late final Set<String> _locationPieces = Set.from(element!.location
        .toString()
        .split(locationSplitter)
        .where((s) => s.isNotEmpty));
  
    @override
    Set<String> get locationPieces => _locationPieces;
  
    static const Set<String> _specialFeatures = {
      // Replace the @override annotation with a feature that explicitly
  
negative.code: 
    String? get filePath;
  
    /// Returns the fully qualified name.
    ///
    /// For example: libraryName.className.methodName
    @override
    late final String fullyQualifiedName = _buildFullyQualifiedName();
  
    late final String _fullyQualifiedNameWithoutLibrary =
        fullyQualifiedName.replaceFirst('${library!.fullyQualifiedName}.', '');
  