Yes, lambdas return the last expression. `Unit` is...

# getting-started

[kevinmost]

Yes, lambdas return the last expression. Unit is basically Void, but the Java compiler doesn't know that. What it sees is "I need to provide a lambda that returns an instance of some type that some 3rd-party library is providing". In this case being Unit, of course, so you'd use Unit.INSTANCE.