https://api.drupal.org/api/drupal/core%21modules%21image%21tests%21src%21Kernel%21ImageStyleCustomStreamWrappersTest.php/property/ImageStyleCustomStreamWrappersTest%3A%3AfileSystem/11.x
ImageStyleCustomStreamWrappersTest::$fileSystem | Drupal API
filesystemdrupalapi
https://api.drupal.org/api/drupal/core%21modules%21image%21tests%21src%21Kernel%21ImageStyleCustomStreamWrappersTest.php/class/ImageStyleCustomStreamWrappersTest/8.9.x
class ImageStyleCustomStreamWrappersTest | Drupal API
classdrupalapi