Use Tensorboard Writer to track multiple model graph at once

tensorboard
1

I have a model which was constructed by 2 sub-models. I tried to log the 2 models graph structure to Tensorboard using

writer.add_graph(model1, input1)
writer.add_graph(model2, input2)

I want to view the structure of both models, but Tensorboard will overwrite the first graph with the latter one.