Java package logic location

Hello Java Team, can you please give me a jump start on the Java code? I can't figure it out. Where are the packages/the number calculated and populated at /rhn/systems/SystemList.do. I found "rhn/frontend/dto/SystemOverview.java" and "BaseDto" but they contain no loading logic. "setOutdatedPackages" from SystemOverview.java is not being used anywhere. I want to have a look if/how it is feasible to (conditionally?) filter out modular packages to make the overview look nicer. Thank you and best wishes, Stefan