Iterates over the event handler registry and execute each found
    handler.

    It takes the event name and its `data`, passing the return of
    data to the found handlers.

def process_external(event_name, data):
    """Iterates over the event handler registry and execute each found
    handler.

    It takes the event name and its `data`, passing the return of
    data to the found handlers.
    """
    for handler in find_external_handlers(event_name):
        try:
            handler(data)
        except Exception as exc:
            logger.warning(
                (u'One of the handlers for the event "{}" has failed with the '
                 u'following exception: {}').format(event_name, str(exc)))
            if getsetting('DEBUG'):
                raise exc