'Determines the device bus and it\'s hypervisor assigned address.'

@staticmethod
def _get_device_bus(bdm):

    if (bdm['disk_bus'] == constants.CTRL_TYPE_SCSI):
        address = ':'.join(['0', '0', str(bdm['drive_addr']), str(bdm['ctrl_disk_addr'])])
        return objects.SCSIDeviceBus(address=address)
    elif (bdm['disk_bus'] == constants.CTRL_TYPE_IDE):
        address = ':'.join([str(bdm['drive_addr']), str(bdm['ctrl_disk_addr'])])
        return objects.IDEDeviceBus(address=address)
