'Error handler.
This is run by the worker when the task fails.
Arguments:
exc (Exception): The exception raised by the task.
task_id (str): Unique id of the failed task.
args (Tuple): Original arguments for the task that failed.
kwargs (Dict): Original keyword arguments for the task that failed.
einfo (~billiard.einfo.ExceptionInfo): Exception information.
Returns:
None: The return value of this handler is ignored.'

def on_failure(self, exc, task_id, args, kwargs, einfo):

    pass
