You don’t need to use the constructor syntax to have an object inherit prototypes from another.
EDIT: I said assign method earlier, I meant create. The assign method is the pre-ES6 way of creating object instances. Object.create() is used to inherit prototypes. That’s such a common mix-up that I’m embarrassed I didn’t catch it.
(Of course I can and do use ES6 when coding for other people, I write to whatever standard is established in a codebase.)