Fatal error: Uncaught Error: Call to undefined method Magento\GroupedProduct\Model\Product\Type\Grouped::getUsedProducts() in /var/www/vhosts/blacktulipflowers.qa/httpdocs/app/code/Ktpl/Custom/Helper/Data.php:114 Stack trace: #0 /var/www/vhosts/blacktulipflowers.qa/httpdocs/app/design/frontend/Magento/newtulip/Magento_Catalog/templates/product/list.phtml(99): Ktpl\Custom\Helper\Data->getDiscountPer(Object(Magento\Catalog\Model\Product\Interceptor)) #1 /var/www/vhosts/blacktulipflowers.qa/httpdocs/vendor/magento/framework/View/TemplateEngine/Php.php(59): include('/var/www/vhosts...') #2 /var/www/vhosts/blacktulipflowers.qa/httpdocs/vendor/magento/framework/View/Element/Template.php(270): Magento\Framework\View\TemplateEngine\Php->render(Object(Magento\Catalog\Block\Product\ListProduct\Interceptor), '/var/www/vhosts...', Array) #3 /var/www/vhosts/blacktulipflowers.qa/httpdocs/vendor/magento/framework/View/Element/Template.php(300): Magento\Framework\View\Element\Template->fetchView('/var/www/vhosts...') #4 /var/www/vhosts/b in /var/www/vhosts/blacktulipflowers.qa/httpdocs/app/code/Ktpl/Custom/Helper/Data.php on line 114