### Problem/Motivation Drupal 11.4.0 converted `ResponsiveImageFormatter` to constructor promotion and, in the same change, added a typed property: `protected FileUrlGeneratorInterface $fileUrlGenerator;` ([change record](https://www.drupal.org/node/3291487)). No core release before 11.4 declared that property on the class at all. `LightboxResponsiveImageFormatter` extends `ResponsiveImageFormatter` and redeclares the same property without a type, which PHP rejects as an incompatible redeclaration: ``` Fatal error: Type of Drupal\lightbox_responsive\Plugin\Field\FieldFormatter\LightboxResponsiveImageFormatter::$fileUrlGenerator must be Drupal\Core\File\FileUrlGeneratorInterface (as in class Drupal\responsive_image\Plugin\Field\FieldFormatter\ResponsiveImageFormatter) in modules/contrib/lightbox/modules/lightbox_responsive/src/Plugin/Field/FieldFormatter/LightboxResponsiveImageFormatter.php on line 24 ``` The fatal is raised during field formatter plugin discovery, where `AttributeClassDiscovery` calls `class_exists()` on every formatter class it finds. It therefore breaks any request that builds an entity view display, and update.php with it, whether or not the Lightbox responsive image formatter is configured on a single field anywhere on the site. ### Steps to reproduce 1. Install Drupal 11.4.x. 2. Enable the Lightbox responsive image formatter submodule. 3. Request any page that renders an entity, or run update.php. ### Proposed resolution Type the redeclared property so that it matches the parent: ```php protected FileUrlGeneratorInterface $fileUrlGenerator; ``` Typing the declaration is preferable to removing it, because the module supports `^10.3 || ^11`. On every core version before 11.4 the parent declares no such property, so removing it would turn the assignment in `create()` into a dynamic property, deprecated since PHP 8.2. A redeclaration carrying the identical type is invariant with the parent, so the same line is valid on 11.4 too. Checked against 10.3, 10.4, 10.5, 11.0, 11.1, 11.2, 11.3 and 11.4: only 11.4 declares the property, and it declares it with exactly this type. `LightboxImageFormatter` extends the `image` module's `ImageFormatter`, which received the same treatment in 11.4 for `$currentUser`, `$imageStyleStorage` and `$fileUrlGenerator`, but it redeclares none of them, so it needs no change. ### Also on the merge request The `phpstan` job was already red on 1.x, on deprecations that core 11.4 and 11.3 introduced: `image_style_options()` and `_responsive_image_build_source_attributes()`. Both are bridged with `DeprecationHelper::backwardsCompatibleCall()` on the same merge request, so that the job is green on the current and the previous major. This also covers #3577503. ### Remaining tasks Review the merge request. ### User interface changes None. ### API changes None. ### Data model changes None. --- AI-Generated: Yes (Claude Code was used to help draft this issue summary and to write the fix on the merge request. I reviewed the work and confirmed on a Drupal 11.4 site that the fatal is raised without the change and gone with it.)