Regtest in BitcoinJ

[Alula]

For some conceptual testing purposes, I want to make changes to the Block generation rewarding algorithm in BitcoinJ.
So far I have cloned BitcoinJ in eclipse and have built it successfully. I also have good theoretical understanding of
Bitcoin protocol however, I'm challenged to find out in which class the rewarding algorith is implemented. How can I also
test my changes in Regression test mode. Thank you very much.