Well I don't see how you'd even accomplish it with a class or method? You basically just want a boolean for "was true last time". Also in many programming languages you'd actually explicitly fire an event when something happens and allow callers to register for that event, instead of testing a condition regularly and triggering something when the state changes. It's a case of where typical C2 style is different to traditional programming.
In C2's case, it stores a separate boolean per condition, since each condition needs to track its state independently. Actually the specific C2 implementation is based on tick counts, but if you're just learning to program, that's not really important.