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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def schedule(identifier, **kwargs):
    '''Schedule a harvest job to run periodically'''
    source = actions.schedule(identifier, **kwargs)
    msg = 'Scheduled {source.name} with the following crontab: {cron}'
    log.info(msg.format(source=source, cron=source.periodic_task.crontab))