module 'torch.onnx' has no attribute 'OperatorExportTypes'

[geekac]

I run this code in Jupyter Notebook，but one error occurs:
`import torch
import torchvision.models
import hiddenlayer as hl

VGG16 with BatchNorm

model = torchvision.models.vgg16()

Build HiddenLayer graph

Jupyter Notebook renders it automatically

hl.build_graph(model, torch.zeros([1, 3, 224, 224]))`

AttributeError: module 'torch.onnx' has no attribute 'OperatorExportTypes'

And I run the code under Ubuntu16.04, pytorch 0.4.0