It is "erased" in this example in the sense that the hashes are just strings at runtime, and not other objects instead. That's because the `generateHash` functi

It is "erased" in this example in the sense that the hashes are just strings at runtime, and not other objects instead. That's because the `generateHash` function in the article's example uses `as Hash` to tell the compiler "yes, I know I'm only returning a string here, but trust me, this is actually a `string & { [__brand]: 'Hash' }`". That `as Hash` is known as a type assertion in Typescript and is normally used when the developer knows something info about the code that Typescript can't.