Implementation
Usages
1. \Magento\Backend\Model\Url.php::XML_PATH_USE_SECURE_KEY
Details: How is \Magento\Backend\Model\Url::useSecretKey()
implemented and used?
2. \Magento\Config\Model\Config\Backend\Admin\Custom::XML_PATH_ADMIN_SECURITY_USEFORMKEY
It is never used.