Handles redirect back to the dashboard when save is clicked
        (eg not save and continue editing), by checking for a redirect
        response, which only occurs if the form is valid.

def handle_save(self, request, response):
        """
        Handles redirect back to the dashboard when save is clicked
        (eg not save and continue editing), by checking for a redirect
        response, which only occurs if the form is valid.
        """
        form_valid = isinstance(response, HttpResponseRedirect)
        if request.POST.get("_save") and form_valid:
            return redirect("admin:index")
        return response