How do we check if colab.research.google.com is down?
1) We check the colab.research.google.com server to see if it is responding and we do this from a region
closest to you. This test we perform simulates what an actual web browser (e.g. Safari, Chrome,
Firefox) would do when trying to visit the website.
2) We determine if the colab.research.google.com server is returning an error message that indicates some
sort of problem. These types of errors generally mean that a visitor -- you -- would also have
trouble using or visiting the service.
3) We return the results of our test from our servers and let you know if colab.research.google.com is up or down.