What's the conventional directory for classes in an Ember project?

If I create a custom class according to https://guides.emberjs.com/release/object-model/classes-and-instances/,

e.g.

// person.js
import EmberObject from '@ember/object';

const Person = EmberObject.extend({
  say(thing) {
    alert(thing);
  }
});

Is there a conventional directory in the ember project for person.js?

None of these conventional directories seem quite right...

• adapters/ (specific purpose)
• components/ (specific purpose)
• controllers/ (specific purpose)
• helpers/ (specific purpose)
• models/ (for actual DS Models)
• routes/ (specific purpose)
• styles/ (not js)
• templates/ (not js)
• serializers/ (specific purpose)
• utils/ (too generic)