Why I met this error "IndentationError: unexpected indent" when running the 2nd step of "training"?

[tiesanguaixia]

I ran this code in README.md

usage: train.py [-h] [--backbone {resnet,xception,drn,mobilenet}]
            [--out-stride OUT_STRIDE] [--dataset {pascal,coco,cityscapes}]
            [--use-sbd] [--workers N] [--base-size BASE_SIZE]
            [--crop-size CROP_SIZE] [--sync-bn SYNC_BN]
            [--freeze-bn FREEZE_BN] [--loss-type {ce,focal}] [--epochs N]
            [--start_epoch N] [--batch-size N] [--test-batch-size N]
            [--use-balanced-weights] [--lr LR]
            [--lr-scheduler {poly,step,cos}] [--momentum M]
            [--weight-decay M] [--nesterov] [--no-cuda]
            [--gpu-ids GPU_IDS] [--seed S] [--resume RESUME]
            [--checkname CHECKNAME] [--ft] [--eval-interval EVAL_INTERVAL]
            [--no-val]

But I was told that

File "", line 2
[--out-stride OUT_STRIDE] [--dataset {pascal,coco,cityscapes}]
^
IndentationError: unexpected indent

Thank u!