gtk/print.go
func (po *PrintOperation) SetCustomTabLabel(label string) {
	cstr := C.CString(label)
	defer C.free(unsafe.Pointer(cstr))
	C.gtk_print_operation_set_custom_tab_label(po.native(), (*C.gchar)(cstr))
}
func (po *PrintOperation) SetCustomTabLabel(label string) {
	cstr := C.CString(label)
	defer C.free(unsafe.Pointer(cstr))
	C.gtk_print_operation_set_custom_tab_label(po.native(), (*C.gchar)(cstr))
}
// SetCustomTabLabel() is a wrapper around gtk_print_operation_set_custom_tab_label().