https://api.drupal.org/api/drupal/core%21tests%21Drupal%21KernelTests%21Core%21Plugin%21FactoryTest.php/class/FactoryTest/8.9.x
class FactoryTest | Drupal API
classdrupalapi
https://api.drupal.org/api/drupal/core%21tests%21Drupal%21KernelTests%21Core%21Plugin%21FactoryTest.php/10
FactoryTest.php | Drupal API
phpdrupalapi