Refs #15241 -- Further clarifications to the generic view migration docs.

Class-based views don't provide a ``context_processors`` argument.

Instead, you subclass the view, overriding

:meth:`TemplateResponseMixin.render_to_response()`. For example::

:meth:`TemplateResponseMixin.render_to_response()`, and passing in

a context instance that has been instantiated with the processors

you want to use. For example::

    class MyListView(ListView):

        def render_to_response(self, context, **kwargs):

            return super(MyListView, self).render_to_response(

                    RequestContext(self.request, context, processors=[custom_processor]), **kwargs)

                    RequestContext(self.request,

                                   context,

                                   processors=[custom_processor]),

                    **kwargs)