XMLTable question

In V2 this does not work, why ?

var obj = new AW.UI.Grid;

var grid_model=new AW.XML.Table;
grid_model.setURL("http://localhost/grids/f.xml");
grid_model.setRows('//RealTime/*');
grid_model.request();


obj.setDataModel(grid_model);<-----This does not exist ? Why?
How to bind the source with the grid ?