Like alot of written code that doesn't really matter to the computer, I do it as a signal to the reader: you _shouldn't_ be messing with these variable/methods

Like alot of written code that doesn't really matter to the computer, I do it as a signal to the reader: you _shouldn't_ be messing with these variable/methods just to use the class. As often noted, someone can and will still go mess with them if they want to, but at least now it's obvious.