Can't find GridViewRelation Collection Editor

[Naunton]

I am new user for Telerik , recently learning RadGridView tutorial --> Hierarchical Grid --> GridViewBinding to Hierarchical Data
I do as tutorial, when arrive at "Define Relation" I can't find "GridViewRelation Collection Editor" as shown in tutorial.

Pls,
Is there anyone can tell me where I can get "GridViewRelation Collection Editor"?

Thanks and Best Regards
Naunton

[Naunton]

Found it now, property named "Relations" .