Select First Node

How can i select ( tree.selectItem ) the first Node of a X Level if i don’y know the ID?

You can select item by index if you know its parentID

Select first item on top level
      tree.selectItem(tree.getItemIdByIndex(0,0));

Select first item in some branch where parent_if = PID

      tree.selectItem(tree.getItemIdByIndex(PID,0));