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:     required this.fixCount,
    });
  }
  
negative.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].
    ///
    /// The keys of the map are the unique names of the lint codes without the
    /// `LintCode.` prefix. Generally the unique name is the same as the name of
    /// the lint, so most of the keys are constants defined by [LintNames]. But
    /// when a lint produces multiple codes, each with a different unique name,
    /// the unique name must be used here.
    static final Map<String, List<ProducerGenerator>> lintProducerMap = {
      LintNames.always_declare_return_types: [
        AddReturnType.newInstance,
  