A bug in utils.py

[ppllracing]

I met this Error
Traceback (most recent call last):
File "RGB2point/inference.py", line 3, in
from utils import predict
File "RGB2point/utils.py", line 157, in
class EMDLoss(nn.Module):
NameError: name 'nn' is not defined

There should be "import torch.nn as nn" in the utils.py.