How Does Git Know What a Python Function/Class Definition Looks Like?

I really like the "TIL" format. I tweeted this a few weeks ago and it seemed to have really resonated with people.

Very thin content. There were really only two options: regex or parser. This is close to "You won't believe what happened next" level of content.

So uhm, what happens if someone puts class Datasette: in a multiline string?