https://api.drupal.org/api/drupal/core%21tests%21Drupal%21Tests%21Core%21Form%21FormSubmitterTest.php/class/FormSubmitterTest/9
class FormSubmitterTest | Drupal API
classdrupalapi
https://api.drupal.org/api/drupal/core%21tests%21Drupal%21Tests%21Core%21Form%21FormSubmitterTest.php/function/FormSubmitterTest%3A%3AsetUp/8.9.x
function FormSubmitterTest::setUp | Drupal API
functionsetupdrupalapi