Javascript between cells in Google Colab

I’m trying to get ipyvizzu, a JS charting library’s Jupyter Notebook integration, to work inside Google Colab. It depends on Jupyter’s behavior that generated javascript codes are put in the same scope throughout the notebook. Basically, the code snippet below would work in Jupyter Notebook. However, it does not work in Google Colab, because Colab seems to put every cell output in a separate iframe. Can I change this behavior of Colab somehow? Or is there any solution to this problem?

from IPython.display import display_javascript
display_javascript("var a = 10", raw=True)
display_javascript("console.log(a)", raw=True)

Error evaluating Javascript output: ReferenceError: a is not defined

(not) working example:
https://colab.research.google.com/drive/1FcAuHwqinsnBiaBALUguFzIw1wzoU1sj?usp=sharing