anchor.diff:    final List<int> _bytes;
     int _byteOffset = 0;
     List<String> _stringTable = const [];
  +  late Map<int, Name?> _nameCache;
     List<Uri> _sourceUriTable = const [];
     List<Constant> _constantTable = const <Constant>[];
     late List<CanonicalName> _linkTable;
  
positive.code: import '../ast.dart';
  import '../transformations/flags.dart';
  import 'tag.dart';
  
  class ParseError {
    final String? filename;
  
negative.code:         new List<int>.generate(length, (_) => readUInt30(), growable: false);
      // Read the WTF-8 encoded strings.
      int startOffset = 0;
  
      // Reset name cache here to make any index into it always
      // be about the corresponding string table entry.
      _nameCache = {};
      _stringTable = new List<String>.generate(length, (int index) {
        String result = readStringEntry(endOffsets[index] - startOffset);
        startOffset = endOffsets[index];
  