[pygtk] Treeview highest level only sort.

[HansPeter]

Hi,

I am using a TreeStore and attach it to a TreeView and add columns to
it.
Currently I have set tvcolumn1.set_sort_column_id(-1) to disable
ordering.

Is it possible to have sorting only on the first level of the tree
leaving the order of the children, grand children intact?

regards HansPeter