anchor.diff:      int stackHeight = enterLocalScope();
       visitChildren(node.function);
       visitList(node.initializers, this);
  +    if (!isOutline) {
  +      checkInitializers(node);
  +    }
       exitLocalScope(stackHeight);
       classTypeParametersAreInScope = false;
       visitList(node.annotations, this);
  
positive.code:   }
  
    visitProgram(Program program) {
      for (var library in program.libraries) {
        for (var class_ in library.classes) {
          if (!classes.add(class_)) {
            throw 'Class $class_ declared more than once';
          }
        }
        library.members.forEach(declareMember);
        for (var class_ in library.classes) {
          class_.members.forEach(declareMember);
        }
      }
      visitChildren(program);
      for (var library in program.libraries) {
        library.members.forEach(undeclareMember);
        for (var class_ in library.classes) {
          class_.members.forEach(undeclareMember);
        }
      }
    }
  
  
negative.code:     parent = oldParent;
    }
  }
  
  void checkInitializers(Constructor constructor) {
    // TODO(ahe): I'll add more here in other CLs.
  }
  