code: def _monkey_inline(model, admin_class_instance, metadata_class, inline_class, admin_site):
      
      if model in metadata_class._meta.seo_models:
          # *Not* adding to the class attribute "inlines", as this will affect
          # all instances from this class. Explicitly adding to instance attribute.
          admin_class_instance.__dict__['inlines'] = admin_class_instance.inlines + [inline_class]
  
          # Because we've missed the registration, we need to perform actions
          # that were done then (on admin class instantiation)
          inline_instance = inline_class(admin_class_instance.model, admin_site)
          admin_class_instance.inline_instances.append(inline_instance)
docs: Monkey patch the inline onto the given admin_class instance.