DiscountBase::prepareCouponsResult

protected function prepareCouponsResult(MainResult $couponsResult): string
{
	$commonList = [];
	$errorList = $couponsResult->getErrors();
	$error = reset($errorList);

	/** @var array $list */
	$list = $error->getCustomData();
	foreach (array_keys($list) as $coupon)
	{
		$commonList[] = $coupon.' - '.$list[$coupon];
	}
	return $error->getMessage().': '.implode(', ', $commonList);

}