def METHOD_NAME(self, request, view, obj=None):
    if hasattr(view, 'parent_model'):
        get_object_or_400(view.parent_model, pk=view.kwargs['pk'])
        return True
    else:
        if obj:
            return True
        if hasattr(view, 'model'):
            return check_user_access(request.user, view.model,
                                     'add', request.data)
        return True