anchor.diff:    visitPrefixedIdentifier(PrefixedIdentifier node) {
       node.safelyVisitChild(node.prefix, this);
       
  -    if (references[node.prefix] is List) {
  +    if (libs.containsKey(node.prefix)) {
         
         // if (node.identifier.toString() == 'Variable') {
         //   print(references[node.prefix].source.source);
         //   print(source);
         // }
         
  -      references[node.prefix].forEach((Our.LibraryElement lib) {
  +      libs[node.prefix].forEach((Our.LibraryElement lib) {
           var lookup = lib.lookup(new Our.Name.FromIdentifier(node.identifier), false);
           if (lookup != null) {
             references[node.identifier] = lookup;
  
positive.code:   Our.LibraryElement library;
  
    Map<AstNode, Our.NamedElement> declaredElements;
    Map<Expression, dynamic> references = {};
    Map<String, dynamic> scope;
    
    Source source;
  
negative.code:     var lib_getter_element = library.lookup(getter, false);
      var lib_setter_element = library.lookup(setter, false);
  
      
      
      if (local_getter_element != null) 
        {
          references[node] = local_getter_element;
  