Jira source code of REST API classes

I wanted to learn from Jira source code how they do certain things in the REST API, but I have a hard time to find it in the Jira source zip.

Do you know in which package I find the REST implementation in Jira source code?


The platform rest calls are bundled in a plugin:
jira-components > jira-plugins > jira-rest > jira-rest-plugin

However some api calls might be scattered across other plugins…


Thank you very much!