Five-fold cross-validation for the UNET model

[Tkrismile]

When using the UNET model on the BTCV dataset, you specified a fold count, but the main.py file contains no code related to cross-validation. Additionally, passing --fold=0 results in an error:
usage: main.py [-h] [--checkpoint CHECKPOINT] [--logdir LOGDIR]
[--pretrained_dir PRETRAINED_DIR] [--data_dir DATA_DIR]
[--json_list JSON_LIST]
[--pretrained_model_name PRETRAINED_MODEL_NAME]
[--save_checkpoint] [--max_epochs MAX_EPOCHS]
[--batch_size BATCH_SIZE] [--sw_batch_size SW_BATCH_SIZE]
[--optim_lr OPTIM_LR] [--optim_name OPTIM_NAME]
[--reg_weight REG_WEIGHT] [--momentum MOMENTUM] [--noamp]
[--val_every VAL_EVERY] [--distributed]
[--world_size WORLD_SIZE] [--rank RANK] [--dist-url DIST_URL]
[--dist-backend DIST_BACKEND] [--workers WORKERS]
[--model_name MODEL_NAME] [--pos_embed POS_EMBED]
[--norm_name NORM_NAME] [--num_heads NUM_HEADS]
[--mlp_dim MLP_DIM] [--hidden_size HIDDEN_SIZE]
[--feature_size FEATURE_SIZE] [--in_channels IN_CHANNELS]
[--out_channels OUT_CHANNELS] [--res_block] [--conv_block]
[--use_normal_dataset] [--a_min A_MIN] [--a_max A_MAX]
[--b_min B_MIN] [--b_max B_MAX] [--space_x SPACE_X]
[--space_y SPACE_Y] [--space_z SPACE_Z] [--roi_x ROI_X]
[--roi_y ROI_Y] [--roi_z ROI_Z] [--dropout_rate DROPOUT_RATE]
[--RandFlipd_prob RANDFLIPD_PROB]
[--RandRotate90d_prob RANDROTATE90D_PROB]
[--RandScaleIntensityd_prob RANDSCALEINTENSITYD_PROB]
[--RandShiftIntensityd_prob RANDSHIFTINTENSITYD_PROB]
[--infer_overlap INFER_OVERLAP] [--lrschedule LRSCHEDULE]
[--warmup_epochs WARMUP_EPOCHS] [--resume_ckpt] [--resume_jit]
[--smooth_dr SMOOTH_DR] [--smooth_nr SMOOTH_NR]
main.py: error: unrecognized arguments: --fold=5