NotNothing

Copied from kafka.utils.NotNothing This is a trick to prevent the compiler from inferring the Nothing type in cases where it would be a bug to do so. An example is the following method:

def body[T <: AbstractRequest](implicit classTag: ClassTag[T], nn: NotNothing[T]): T

If we remove the nn parameter and we invoke it without any type parameters (e.g. request.body), Nothing would be inferred, which is not desirable. As defined above, we get a helpful compiler error asking the user to provide the type parameter explicitly.