public abstract DonationFormLayoutEntity updateEntity(DonationFormRequest source, @MappingTarget DonationFormLayoutEntity entity);

private String value;
private LocalDate dateChanged;

    protected DonationFormModeEntity responseToFormModeEntity(DonationFormModeResponse source, DonationFormLayoutEntity entity) {
        DonationFormMode originalMode = entity.getFormMode().getValue();
        DonationFormMode updatedMode = DonationFormMode.valueOf(source.getValue());
        DonationFormModeEntity.DonationFormModeEntityBuilder formModeBuilder = DonationFormModeEntity.builder().value(updatedMode);
        if (Objects.equals(originalMode, updatedMode) == false) {
            formModeBuilder.dateChanged(LocalDate.now());
        } else {
            formModeBuilder.dateChanged(entity.getFormMode().getDateChanged());
        }
        return formModeBuilder.build();
    }

@Mapping(target = "formMode", expression = "java(responseToFormModeEntity(source.getFormMode(), entity))")