What's the lambda meant to do? Where is relay_github() used?

[ChaiBapchya]

I can see a function relay_github in handler.py file
Q. What's the purpose of it?
A. It verifies the signature and if true invokes Jenkins
So I am guessing this lambda function tries to act as a receiver of input from Github via webhooks and relay the info (if verified signature) to Jenkins CI

Correct?

Q. Where is it called?
I can see the definition but I can't see it called
Is this a separate API entry-point?