https://api.drupal.org/api/drupal/core%21modules%21system%21tests%21src%21Functional%21System%21PageNotFoundTest.php/property/PageNotFoundTest%3A%3Amodules/11.x
PageNotFoundTest::$modules | Drupal API
modulesdrupalapi
https://api.drupal.org/api/drupal/core%21modules%21system%21tests%21src%21Functional%21System%21PageNotFoundTest.php/class/PageNotFoundTest/10
class PageNotFoundTest | Drupal API
classdrupalapi