Runtime Error when saving model about biggan-pytorch HOT 6 CLOSED

11/250 (  4.00%) (TE/ETA: 0:13 / 5:18) itr: 11, G_loss : +0.418, D_loss_real : +0.149, D_loss_fake : 12/250 (  4.40%) (TE/ETA: 0:13 / 4:55) itr: 12, G_loss : -0.430, D_loss_real : +0.369, D_loss_fake : 13/250 (  4.80%) (TE/ETA: 0:13 / 4:36) itr: 13, G_loss : -0.668, D_loss_real : +0.540, D_loss_fake : 14/250 (  5.20%) (TE/ETA: 0:14 / 4:20) itr: 14, G_loss : -0.389, D_loss_real : +0.516, D_loss_fake : 15/250 (  5.60%) (TE/ETA: 0:14 / 4:05) itr: 15, G_loss : -0.387, D_loss_real : +1.293, D_loss_fake : 16/250 (  6.00%) (TE/ETA: 0:14 / 3:53) itr: 16, G_loss : +0.582, D_loss_real : +1.693, D_loss_fake : 17/250 (  6.40%) (TE/ETA: 0:15 / 3:41) itr: 17, G_loss : +0.666, D_loss_real : +0.569, D_loss_fake : 18/250 (  6.80%) (TE/ETA: 0:15 / 3:32) itr: 18, G_loss : +1.341, D_loss_real : +0.089, D_loss_fake : 19/250 (  7.20%) (TE/ETA: 0:15 / 3:23) itr: 19, G_loss : +0.691, D_loss_real : +0.333, D_loss_fake : 20/250 (  7.60%) (TE/ETA: 0:16 / 3:15) itr: 20, G_loss : +0.195, D_loss_real : +0.000, D_loss_fake : +1.365 Saving weights to weights/BigGAN_C100_seed2_Gch64_Dch64_bs50_nDs4_Glr2.0e-04_Dlr2.0e-04_Gnlrelu_Dnlrelu_GinitN02_DinitN02_ema...
Saving weights to weights/BigGAN_C100_seed2_Gch64_Dch64_bs50_nDs4_Glr2.0e-04_Dlr2.0e-04_Gnlrelu_Dnlrelu_GinitN02_DinitN02_ema/copy0...
Traceback (most recent call last):
  File "train.py", line 227, in <module>
    main()
  File "train.py", line 224, in main
    run(config)
  File "train.py", line 206, in run
    state_dict, config, experiment_name)
  File "/workspace/BigGAN-PyTorch/train_fns.py", line 140, in save_and_sample
    z_=z_)
  File "/workspace/BigGAN-PyTorch/utils.py", line 892, in sample_sheet
    z_.sample_()
AttributeError: 'Tensor' object has no attribute 'sample_'