I’ve done the lesson.

But I don’t understand the last extra task:
“Create class called Catalog that holds all of the Media items in our library.”

What should I really do?

I faced the same task in next lesson. I created class that constructs instance, which contains another classes.
Is it an answer?

class SchoolCatalog {
  constructor(School, PrimarySchool, Middle, HighSchool) {
    this._School = School;
    this._PrimarySchool = PrimarySchool;
    this._Middle = Middle;
    this._HighSchool = HighSchool; 
  get School () {
     return this._School;

const catalogue = new SchoolCatalog(School, PrimarySchool, Middle, HighSchool);
const schoolInstance = new catalogue.School('1', '2', '3');