/**
* @uses \Magento\Framework\App\Config\Data::getValue()
* https://github.com/magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/lib/internal/Magento/Framework/App/Config/Data.php#L47-L62
*
* 2015-12-26
* https://mage2.pro/t/357
* «The @uses \Magento\Framework\App\Config::getValue() method
* has a wrong PHPDoc type for the $scopeCode parameter».
*
* Метод возвращает null или $default, если данные отсутствуют:
* @see \Magento\Framework\App\Config\Data::getValue()
* https://github.com/magento/magento2/blob/6ce74b2/lib/internal/Magento/Framework/App/Config/Data.php#L47-L62
*
* 2015-10-09
* https://mage2.pro/t/128
* https://github.com/magento/magento2/issues/2064
*
* @param string $key
* @param null|string|int|ScopeA|Store|IConfigData|ConfigData $scope [optional]
* @param mixed|callable $default [optional]
* @return array|string|null|mixed
*/
function df_cfg($key, $scope = null, $default = null)
{
/** @var array|string|null|mixed $result */
$result = $scope instanceof IConfigData ? $scope->getValue($key) : df_cfg_m()->getValue($key, ScopeS::SCOPE_STORE, $scope);
return df_if(df_cfg_empty($result), $default, $result);
}