7 files declare their use of GroupContentMenuInterface in Group Content Menu 8

GroupContentMenu.php in src/Entity/GroupContentMenu.php

GroupContentMenuController.php in src/Controller/GroupContentMenuController.php

GroupContentMenuForm.php in src/Form/GroupContentMenuForm.php

GroupMenuBlock.php in src/Plugin/Block/GroupMenuBlock.php

group_content_menu.module in ./group_content_menu.module

Provides a group content menu entity type.

group_content_menu.post_update.php in ./group_content_menu.post_update.php

Install hooks for group_content_menu module.

NodeFormAlter.php in src/NodeFormAlter.php