anchor.diff:      final resolvedLibrary =
           await target.session.getResolvedLibraryByElement(target.library);
       final targetDeclaration = resolvedLibrary.getElementDeclaration(target);
  -    final unit = targetDeclaration.parsedUnit.unit;
  +    final unit = targetDeclaration.resolvedUnit.unit;
       final location = unit.lineInfo?.getLocation(nameOffset);
       if (location != null) {
         locationString = "${location.lineNumber}:${location.columnNumber}";
  
positive.code:   // we will never need to support any members that we don't use locally.
    @override
    noSuchMethod(Invocation invocation) {
      _severe("Missing MixinApplication member");
    }
  }
  
  
negative.code:   @override
    get session => mixin.session;
  
    @override
    get source => mixin.source;
  
    @override
    get nameOffset => -1;
  
    /// Returns true iff this class was declared using the syntax
    /// `class B = A with M;`, i.e., if it is an explicitly named mixin
    /// application.
  