human
Complete the below
@connect_on_app_finalize
def add_backend_cleanup_task(app):

    ''''Task used to clean up expired results.
    If the configured backend requires periodic cleanup this task is also
    automatically configured to run every day at 4am (requires
    :program:`celery beat` to be running).'
    '''
assistant
#Here is the Python program you requested.
    @app.task(name=u'celery.backend_cleanup', shared=False, lazy=False)
    def backend_cleanup():
        app.backend.cleanup()
    return backend_cleanup