https://api.drupal.org/api/drupal/modules%21image%21image.test/property/ImageFieldTestCase%3A%3Aadmin_user/7.x
ImageFieldTestCase::$admin_user | Drupal API
admin userdrupalapi
https://api.drupal.org/api/drupal/modules%21image%21image.test/function/ImageFieldTestCase%3A%3AsetUp/7.x
function ImageFieldTestCase::setUp | Drupal API
functionsetupdrupalapi