anchor.diff:          _byteStore.put(key, bytes);
         });
   
  -      return new LibraryContext(libraryFile, libraryNode, store);
  +      return new _LibraryContext(libraryFile, libraryNode, store);
       });
     }
   
  
positive.code:   final _fileContentHashMap = <String, String>{};
  
    /**
     * Mapping from library URIs to the linked hash of the library.
     */
    final _linkedHashMap = <Uri, String>{};
  
    /**
     * TODO(scheglov) document and improve
  
negative.code:     return _dependencies;
    }
  
    String get dependencySignature {
      return _dependencySignature ??=
          driver._dependencySignatureMap.putIfAbsent(uri, () {
        computeTransitiveDependencies();
  
        // Add all unlinked API signatures.
  