anchor.diff:  };
   
   // Rewrite certain Flutter IDs (numbers) using prefix matching.
  -const Map<String, String> identifierPrefixRewrites = <String, String>{
  +const Map<String, String> _identifierPrefixRewrites = <String, String>{
     '1': 'one_',
     '2': 'two_',
     '3': 'three_',
  
positive.code: };
  
  // Rewrite certain Flutter IDs (reserved keywords) using exact matching.
  const Map<String, String> identifierExactRewrites = <String, String>{
    'class': 'class_',
    'new': 'new_',
    'switch': 'switch_',
  
negative.code:   static String generateFlutterId(String id) {
      String flutterId = id;
      // Exact identifier rewrites.
      for (final MapEntry<String, String> rewritePair in _identifierExactRewrites.entries) {
        final String shortId = Icon._generateShortId(id);
        if (shortId == rewritePair.key) {
          flutterId = id.replaceFirst(
            rewritePair.key,
            _identifierExactRewrites[rewritePair.key]!,
          );
        }
      }
      // Prefix identifier rewrites.
      for (final MapEntry<String, String> rewritePair in _identifierPrefixRewrites.entries) {
        if (id.startsWith(rewritePair.key)) {
          flutterId = id.replaceFirst(
            rewritePair.key,
            _identifierPrefixRewrites[rewritePair.key]!,
          );
        }
      }
  