So far, you have learned that extending from classes allows you to inherit code (properties and method implementations), but it has the limitation of extending only from one class each time. On the other hand, you can use interfaces to implement multiple behaviors from the same class, but you cannot inherit code in this way. To fill this gap, that is, to be able to inherit code from multiple places, you have traits.

Traits are mechanisms that allow you to reuse code, "inheriting", or rather copy-pasting code, from multiple sources at the same time. Traits, as abstract classes or interfaces, cannot be instantiated; they are just containers of functionality that can be used from other classes.

If you remember, we have some code in the Person class that manages the assignment of IDs. This code is not really part of a person, but rather part of an ID system that could be used by some other entity that has to be identified with IDs too. One way to extract this functionality from Person...