Using Flow with Node through preprocessing

Working with comments is a bit overly verbose. If you'd rather work with straightforward type annotations and extra statements, you will have to turn to some preprocessing, to get rid of the Flow paraphernalia before attempting to run your Node code. The good thing with this is that the required processing can be quite efficient, and practically unnoticeable when you develop; let's get into it, and see how we can get to keep Flow definitions, while not breaking our Node code.