Inside the major() setter method, set the student's major to a backing property "major". If the student's level is Junio

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

  }


}

var student = new Student(3.9, 60);