How to see the connections betwwen all the Src files in Geant4?

as i am new to Geant4 and i have a little bit knowledge of programming. so my question is how can i understand relation between all the src files means how they are connecting and giving me some output.
like i am working on the Example/advanced/radio-protection --in that in stepping action i have created a file and using aStep->GetTotaldeposite() i got deposited energy written in that file of every step. but now i am really unable to understand how it is giving me this output and how it is connected to General particle source ( or primary event generation class ) and giving me this output.
can anyone please help me with this, it will be very helpful for me.
Thanks in advance !