This fixes #257 by providing a None mode (0).
Not having None means that the user needs to use any number outside the enum (to reset the debug mode), which seems hacky to me.
Coverage decreased (-0.002%) to 20.213% when pulling fabab20e8fb365cacf843ebda6bd3adac5360716 on fix-debugPassMode into d44f481ce939d67876cc9bd7788e7d81f288d331 on master.
This fixes #257 by providing a None mode (0). Not having None means that the user needs to use any number outside the enum (to reset the debug mode), which seems hacky to me.