anchor.diff:  
   import 'dart:collection';
   
  +import 'package:analyzer/src/generated/ast.dart' show AstNode;
  +import 'package:analyzer/src/generated/element.dart';
  +import 'package:analyzer/src/generated/java_core.dart';
  +import 'package:analyzer/src/generated/parser.dart' show ParserErrorCode;
  +import 'package:analyzer/src/generated/scanner.dart'
  +    show ScannerErrorCode, Token;
  +import 'package:analyzer/src/generated/source.dart';
   import 'package:analyzer/src/task/model.dart';
   import 'package:analyzer/task/model.dart';
   import 'package:source_span/source_span.dart';
  -
  -import 'ast.dart' show AstNode;
  -import 'element.dart';
  -import 'java_core.dart';
  -import 'scanner.dart' show Token;
  -import 'source.dart';
   
   /**
    * The descriptor used to associate error filters with analysis contexts in
  
positive.code:     StaticWarningCode.UNDEFINED_SUPER_GETTER,
      StaticWarningCode.UNDEFINED_SUPER_SETTER,
      StaticWarningCode.VOID_RETURN_FOR_GETTER,
      TodoCode.TODO
    ];
  
    /**
  
negative.code:     //
      // Manually generated.  FWIW, this get's you most of the way there:
      //
      // > grep 'static const .*Code' (error.dart|parser|scanner.dart)
      //     | awk '{print $3"."$4","}'
      //
      // error.dart:
      //
      AnalysisOptionsErrorCode.PARSE_ERROR,
      AnalysisOptionsWarningCode.UNSUPPORTED_OPTION_WITH_LEGAL_VALUE,
  