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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 run(connection):
 """ Ensure that we have snapshots for a given volume :type connection: boto.ec2.connection.EC2Connection :param connection: EC2 connection object :returns: None """

    volumes = volume_manager.get_watched_volumes(connection)

    for volume in volumes:
        _ensure_snapshot(connection, volume)
        _remove_old_snapshots(connection, volume)