code: func (po *PrintOperation) GetDefaultPageSetup() (*PageSetup, error) {
  	c := C.gtk_print_operation_get_default_page_setup(po.native())
  	if c == nil {
  		return nil, nilPtrErr
  	}
  	obj := glib.Take(unsafe.Pointer(c))
  	return wrapPageSetup(obj), nil
  }
docs: // GetDefaultPageSetup() is a wrapper around gtk_print_operation_get_default_page_setup().