AttributeError: 'tuple' object has no attribute 'size' about attentive-filtering-network HOT 1 CLOSED

Traceback (most recent call last):
File "main.py", line 161, in
train(args, model, device, train_loader, optimizer, epoch, rnn)
File "/home/spoof-reply/afn/src/v1_training.py", line 27, in train
loss = F.binary_cross_entropy(output, target)
File "/home/python27/lib/python2.7/site-packages/torch/nn/functional.py", line 1592, in binary_cross_entropy
if not (target.size() == input.size()):
AttributeError: 'tuple' object has no attribute 'size'

the output type is 'turple'? it should be a 'tensor'?
how I fix this problem?

from attentive-filtering-network.