Expand Telerik RadTreeView (for ASP.net AJAX) on load

I'm wondering why I can't find a straight way to expand all nodes of a static RadTreeView on page load. I first traversed all its properties both from properties pane of Visual Studio and also I checked it from code-behind. I didn't find any single property to tell it to open it in expanded mode. Then I looked at the Telerik's website and unfortunately I didn't find any server-side solution to make it load in expanded mode.

Do you know any ways/tricks to load it in expanded mode?

I found the answer (expanding from code-behind):

if (!IsPostBack)
        {
            foreach (RadTreeNode rtn in RTVControl.Nodes)
            {
                rtn.ExpandChildNodes();
                rtn.Expanded = true;
            }
        }