Taken from: https://labsjs.blob.core.windows.net/sdk/LabsJS-1.0.4/labs.html

To test locally, run:

cd v3/
python bottle_server.py

and visit

http://localhost:8080/office-mix-labshost/labshost.html?lab=http://localhost:8080/opt-office-mix.html?PostMessageLabHost