c_gtk_tree_sortable_set_sort_column_id

Undocumented in source but is binding to C. You might be able to learn more by searching the web for its name.
__gshared extern (C)
void function(GtkTreeSortable* sortable, gint sortColumnId, GtkSortType order) c_gtk_tree_sortable_set_sort_column_id;

Meta