def _fixup_cell_info(cell_info, keys):

    if 'transport_url' not in cell_info:
        return

    # Disassemble the transport URL
    transport_url = cell_info.pop('transport_url')
    try:
        transport_url = rpc.get_transport_url(transport_url)
    except messaging.InvalidTransportURL:
        # Just go with None's
        for key in keys:
            cell_info.setdefault(key, None)
        return

    if not transport_url.hosts:
        return

    transport_host = transport_url.hosts[0]

    transport_field_map = {'rpc_host': 'hostname', 'rpc_port': 'port'}
    for key in keys:
        if key in cell_info:
            continue

        transport_field = transport_field_map.get(key, key)
        cell_info[key] = getattr(transport_host, transport_field)
If the transport_url is present in the cell, derive username,
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/api/openstack/compute/cells.py/_fixup_cell_info