getter and setter = Set the students major to a backing property "_major"

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() {
    return this._major;
  }

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

var student = new Student(3.9, 60);