Project: Build a Library... Error saying this is not defined

Hey guys I’m running my code for the Build a Library project in the intermediate Javascript course and get this reference error saying this is not defined in the Book class. I can’t seem to figure out the issue.

class Media { constructor(title) { this._title = title; this._isCheckedOut = false; this._ratings = []; } get title() { return this._title; } get isCheckedOut() { return this._isCheckedOut; } get ratings() { return this._ratings; } set isCheckedOut(value) { this._isCheckedOut = value; } toggleCheckOutStatus(isCheckedOut) { this.isCheckedOut = !this.isCheckedOut; } getAverageRating() { let ratingsSum = this.ratings.reduce( (accumulator, rating) => accumulator + rating ); return ratingsSum / this.ratings.length; } addRating(value) { this.ratings.push(value); } } class Book extends Media { constructor(author, title, pages) { this._author = author; super(title); this._pages = pages; } get author() { return this._author; } get pages() { return this._pages; } }