Returns the update view that can be specified as the second argument
        to url() in urls.py.

def update(cls):
        """
        Returns the update view that can be specified as the second argument
        to url() in urls.py.
        """

        class NewPopupUpdateView(PopupUpdateView, cls.parent_class):
            model = cls.model
            form_class = cls.form_class
            popup_name = cls.get_class_verbose_name()
            template_name = cls.get_template_name_update()
            permission_required = cls.get_permission_required('update')

            def get_context_data(self, **kwargs):
                kwargs.update(cls.context_for_all)
                kwargs.update(cls.context_for_update)
                return super(NewPopupUpdateView, self).get_context_data(**kwargs)

        return NewPopupUpdateView