Object Literal - Setter Method

class Student {
    constructor(gpa, credits){
        this.gpa = gpa;
        this.credits = credits;
    }
    stringGPA() {
        return (this.gpa).toString();
    }

    get level() {
        if (this.credits >= 90 ) {
            return 'Senior';
        } else if (this.credits >= 60) {
            return 'Junior';
        } else if (this.credits >= 30) {
            return 'Sophomore';
        } else {
            return 'Freshman';
        }
    }

    get major(){
        this._major;
    }

    set major(x){
      if (this.level === "Junior" || this.level === "Senior"){
        this._major=x;
        return this._major;
      }else{
        this._major=x;
        return this._major= 'none';
      }
    }
}

var student = new Student(3.9, 60);
console.log(student.level);
student.major = 'CS';
console.log(student.major);