protected function validateFieldDefinitionCreateStruct(FieldDefinitionCreateStruct $fieldDefinitionCreateStruct, SPIFieldType $fieldType)
    {
        $validationErrors = array();

        if ($fieldDefinitionCreateStruct->isSearchable && !$fieldType->isSearchable()) {
            $validationErrors[] = new ValidationError(
                "FieldType '{$fieldDefinitionCreateStruct->fieldTypeIdentifier}' is not searchable"
            );
        }

        return array_merge(
            $validationErrors,
            $fieldType->validateValidatorConfiguration($fieldDefinitionCreateStruct->validatorConfiguration),
            $fieldType->validateFieldSettings($fieldDefinitionCreateStruct->fieldSettings)
        );
    }