Nullables are a novel approach to testing that allow you to create fast, reliable tests without using mocks (or interfaces). They're a way of "turning off" production code so you can have sociable, state-based tests that don't talk to the outside world.
I'm hosting office hours on May 10th at 9am Pacific / 12pm Eastern / 18:00 CEST for anybody who'd like to discuss these ideas. Bring your code! Details and a calendar reminder are available here:
Cheers,
James