Please describe the problem:
In the doc for this method (TreeView.setCursor) is said 
@param focusColumn A TreeViewColumn, or NULL

in order to not start editing the row you must supply the third param false and
you can pass for column null. But in the source I saw 
gtk_tree_view_set_cursor(getHandle(), path.getHandle(), focusColumn.getHandle(),
startEditing);

And if you pass NULL for focusColumn it will always throw NullPointerException

Steps to reproduce:
1. create TreeView
2. pass null to TreeView.setCursor as second param
3. 


Actual results:
NullPointerException

Expected results:
to be focused on the appropriate row.

Does this happen every time?
yes

Other information: