func (v *TreeModel) GetNColumns() int {
	c := C.gtk_tree_model_get_n_columns(v.native())
	return int(c)
}
func (v *TreeModel) GetNColumns() int {
	c := C.gtk_tree_model_get_n_columns(v.native())
	return int(c)
}
// GetNColumns() is a wrapper around gtk_tree_model_get_n_columns().