      def custom_detail_action(self, request, *args, **kwargs):
          raise NotImplementedError
  
  
  router = SimpleRouter()
  router.register(r'actions', ActionViewSet)
  router.register(r'actions-alt', ActionViewSet, base_name='actions-alt')
  
 
</s> remove         raise NotImplementedError
 </s> add         return Response() </s> remove         raise NotImplementedError
 </s> add         return Response() </s> remove     @action(detail=True)
    def link2(self, request, *args, **kwargs):
        return Response({'method': 'link2'})
 </s> add 
    @action(detail=True, url_path=r'unresolvable/(?P<arg>\w+)', url_name='unresolvable')
    def unresolvable_detail_action(self, request, *args, **kwargs):
        raise NotImplementedError

      def custom_detail_action(self, request, *args, **kwargs):
          raise NotImplementedError
  
    @action(detail=True, url_path=r'unresolvable/(?P<arg>\w+)', url_name='unresolvable')
    def unresolvable_detail_action(self, request, *args, **kwargs):
        raise NotImplementedError

  
  router = SimpleRouter()
  router.register(r'actions', ActionViewSet)
  router.register(r'actions-alt', ActionViewSet, base_name='actions-alt')
  
keep keep add keep keep keep keep keep
 Improvements to ViewSet extra actions (#5605)

* View suffix already set by initializer

* Add 'name' and 'description' attributes to ViewSet

ViewSets may now provide their `name` and `description` attributes
directly, instead of relying on view introspection to derive them.
These attributes may also be provided with the view's initkwargs.

The ViewSet `name` and `suffix` initkwargs are mutually exclusive.

The `action` decorator now provides the `name` and `description` to
the view's initkwargs. By default, these values are derived from the
method name and its docstring. The `name` may be overridden by providing
it as an argument to the decorator.

The `get_view_name` and `get_view_description` hooks now provide the
view instance to the handler, instead of the view class. The default
implementations of these handlers now respect the `name`/`description`.

* Add 'extra actions' to ViewSet & browsable APIs

* Update simple router tests

Removed old test logic around link/action decorators from `v2.3`. Also
simplified the test by making the results explicit instead of computed.

* Add method mapping to ViewSet actions

* Document extra action method mapping 
tests/test_viewsets.py