def METHOD_NAME(node: CephNode, osn, expected_osds):
    out, _ = node.exec_command(
        cmd="sudo cephadm shell -- ceph osd tree --format json-pretty"
    )
    oks = json.loads(out)
    for i in range(len(oks["nodes"])):
        if oks["nodes"][i]["name"] == osn:
            if len(oks["nodes"][i]["children"]) < expected_osds:
                raise AssertionError("Expected OSDs doesn't exist")
            osd_list = oks["nodes"][i]["children"]
            log.info(f"OSDs on {osn} : {osd_list}")
            break