anchor.diff:  
       var errorCode = error.errorCode;
       if (errorCode is LintCode) {
  -      var generators = lintProducerMap[errorCode.name] ?? [];
  +      var generators = lintProducerMap[errorCode.uniqueLintName] ?? [];
         for (var generator in generators) {
           await compute(generator());
         }
  
positive.code:   /// used to create correction producers. The generators are then used to build
    /// fixes for those diagnostics. The generators used for non-lint diagnostics
    /// are in the [nonLintProducerMap].
    static final Map<String, List<ProducerGenerator>> lintProducerMap = {
      LintNames.always_declare_return_types: [
        AddReturnType.newInstance,
  
negative.code: 
    List<ProducerGenerator> _getGenerators(ErrorCode errorCode) {
      if (errorCode is LintCode) {
        return FixProcessor.lintProducerMap[errorCode.uniqueLintName] ?? [];
      } else {
        // todo (pq): consider support for multiGenerators
        return FixProcessor.nonLintProducerMap[errorCode] ?? [];
  