code: func (v *TreeViewColumn) SetSortOrder(order SortType) {
  	C.gtk_tree_view_column_set_sort_order(v.native(), C.GtkSortType(order))
  }
docs: // GtkWidget * 	gtk_tree_view_column_get_button ()
  // void 	gtk_tree_view_column_set_alignment ()
  // gfloat 	gtk_tree_view_column_get_alignment ()
  // void 	gtk_tree_view_column_set_sort_order ()