public function getFieldValidationOptions()
    {
        $fields = new FieldList(
            CheckboxField::create('Required', _t(__CLASS__.'.REQUIRED', 'Is this field Required?'))
                ->setDescription(_t(__CLASS__.'.REQUIRED_DESCRIPTION', 'Please note that conditional fields can\'t be required')),
            TextField::create('CustomErrorMessage', _t(__CLASS__.'.CUSTOMERROR', 'Custom Error Message'))
        );

        $this->extend('updateFieldValidationOptions', $fields);

        return $fields;
    }