anchor.diff:      List<Folder> allContexts = <Folder>[];
       Map<Folder, List<CacheEntry>> entryMap =
           new HashMap<Folder, List<CacheEntry>>();
  +    StringBuffer invalidKeysBuffer = new StringBuffer();
       analysisServer.folderMap
           .forEach((Folder folder, InternalAnalysisContext context) {
         Source source = context.sourceFactory.forUri(sourceUri);
  
positive.code:     _writeResponse(request, (StringBuffer buffer) {
        _writePage(buffer, 'Analysis Server - Cache Entry',
            ['Context: $contextFilter', 'File: $sourceUri'], (HttpResponse) {
          List<CacheEntry> entries = entryMap[folder];
          buffer.write('<h3>Analyzing Contexts</h3><p>');
          bool first = true;
  
negative.code:               entries = <CacheEntry>[];
                entryMap[folder] = entries;
              }
              CacheEntry value = iterator.value;
              if (value == null) {
                if (invalidKeysBuffer.isNotEmpty) {
                  invalidKeysBuffer.write(', ');
                }
                invalidKeysBuffer.write(iterator.key.toString());
              } else {
                entries.add(value);
              }
            }
          }
        }
  