The "grouped_features" variable is generated dynamically in the getGroupedFeatures() method of the ProductLazyArray class:
https://github.com/PrestaShop/PrestaShop/blob/1.7.5.x/src/Adapter/Presenter/Product/ProductLazyArray.php#L353
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The "grouped_features" variable is generated dynamically in the getGroupedFeatures () method of the ProductLazyArray class:
https://github.com/PrestaShop/PrestaShop/blob/1.7.5.x/src/Adapter/Presenter/Product/ProductLazyArray.php#L353