<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">

    <preference for="Magento\Ui\Model\Export\ConvertToCsv" type="Myfitmix\CustomImport\Model\Export\ConvertToCsv" />
		
</config>