https://api.drupal.org/api/drupal/core%21modules%21update%21src%21Form%21UpdateReady.php/property/UpdateReady%3A%3Aroot/10
UpdateReady::$root | Drupal API
rootdrupalapi
https://api.drupal.org/api/drupal/core%21modules%21update%21src%21Form%21UpdateReady.php/property/UpdateReady%3A%3Astate/9
UpdateReady::$state | Drupal API
statedrupalapi