          pass
  
      @action(detail=True, url_name='detail-custom')
      def custom_detail_action(self, request, *args, **kwargs):
          pass
  
  
  router = SimpleRouter()
  router.register(r'actions', ActionViewSet)
  router.register(r'actions-alt', ActionViewSet, base_name='actions-alt')
 
</s> remove         pass
 </s> add         raise NotImplementedError()  # pragma: no cover </s> remove         pass
 </s> add         raise NotImplementedError()  # pragma: no cover </s> remove         pass
 </s> add         raise NotImplementedError()  # pragma: no cover </s> remove         pass
 </s> add         raise NotImplementedError()  # pragma: no cover </s> remove         pass
 </s> add         raise NotImplementedError()  # pragma: no cover
        raise NotImplementedError()  # pragma: no cover
          pass
  
      @action(detail=True, url_name='detail-custom')
      def custom_detail_action(self, request, *args, **kwargs):
        raise NotImplementedError()  # pragma: no cover
  
  
  router = SimpleRouter()
  router.register(r'actions', ActionViewSet)
  router.register(r'actions-alt', ActionViewSet, base_name='actions-alt')
keep keep keep keep replace keep keep keep keep keep
 tests: remove some dead code, use `assert 0` for never called methods (#5973)

* tests: remove some dead code, use `assert 0` for never called methods

* fixup! tests: remove some dead code, use `assert 0` for never called methods 
tests/test_viewsets.py