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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 get_ceph_nodes(relation='ceph'):
 """Query named relation to determine current nodes."""

    hosts = []
    for r_id in relation_ids(relation):
        for unit in related_units(r_id):
            hosts.append(relation_get('private-address', unit=unit, rid=r_id))

    return hosts