fuzzy selector gimp source code

In a project, I want to have a tool performing the same work as the fuzzy selector in Gimp in python. I downloaded the Gimp source code but I can't find the portion of code for the fuzzy selector tool.

I've seen posts like this Gimp fuzzy floodfill but floodfill isn't what I'm searching for.

Could someoune help me to find it? I've searched for tools to search in source code but couldn't find any? I'm completely lost in the huge amount of code owned by Gimp :/

It's not particularly the Gimp code that I'm interested in, but the method used.

Thanks in advance :)