inference_realesrgan.py how work on multi-gpu?

[siestina]

inference_realesrgan.py have argument: parser.add_argument('-g', '--gpu-id', type=int, default=None, help='gpu device to use (default=None) can be 0,1,2 for multi-gpu') but cause exception: error: argument -g/--gpu-id: invalid int value: '0,1'