Warning: Undefined variable $block in /var/www/magento/html/app/design/frontend/bbnt/base/Magento_Theme/templates/html/keyline.phtml on line 3

Fatal error: Uncaught Error: Call to a member function getChildHTML() on null in /var/www/magento/html/app/design/frontend/bbnt/base/Magento_Theme/templates/html/keyline.phtml:3 Stack trace: #0 {main} thrown in /var/www/magento/html/app/design/frontend/bbnt/base/Magento_Theme/templates/html/keyline.phtml on line 3