importError: cannot import name 'flatten_tensor' from 'nnutils'

[sbanwaskar]

While running preprocess.py -
python3 preprocess.py --train ../data/moses/train.txt --split 100 --jobs 16
Traceback (most recent call last):
File "preprocess.py", line 10, in
from fast_jtnn import *
File "/home/shreya/Desktop/jtnn/icml18-jtnn-master/fast_molvae/fast_jtnn/init.py", line 2, in
from jtnn_vae import JTNNVAE
File "/home/shreya/Desktop/jtnn/icml18-jtnn-master/fast_molvae/jtnn_vae.py", line 5, in
from nnutils import create_var, flatten_tensor, avg_pool
ImportError: cannot import name 'flatten_tensor' from 'nnutils'

Can anyone help with this?