def METHOD_NAME(self, index):
    psuid = '0' if index == 1 else '1'
    sysfs_path = '/sys/devices/platform/dell-n3248pxe-cpld.0/psu' + psuid + '_prs'
    found_psu = int(open(sysfs_path).read())
    return 'DELTA' if  found_psu else  ''