def ha_on_error(self, method, exc, my_args, my_kwargs):
pass<EOL>
Callback when exception is caught by the Ha.catch decorator.
        This method is meant to be overloaded.

        :param method: the method that failed.
        :param tuple args: arguments given to the method
        :param dict kwargs: keyword arguments given to the method

        :return: tuple (args, **kwargs) to override the arguments given
        to the next attempt, `None` otherwise.