Base::convertKeysToSnakeCase

protected function convertKeysToSnakeCase($data): array
{
	$converter = new Converter(Converter::KEYS | Converter::RECURSIVE | Converter::TO_SNAKE | Converter::TO_UPPER | Converter::TO_SNAKE_DIGIT);
	$items = $converter->process($data);
	return $this->converterKeysProcessOnAfter($items);
}