title: Super method returning undefined for defined variable in Es6
body: <p>My super method returns undefined for the age variable, I don't know why.</p>
  
  <p>Here's my code:</p>
  
  <pre><code>class customer_info{
  
      constructor(name, age = 50, gender){
          this.name = 'Lambo';
          this.age = age;
          this.gender = 'Male';
      }
  
      getCustomerInfo(){
        let customer_list = {Names: this.name, Age: this.age, Gender: this.gender};
        return customer_list;
      }
  
  }
  
  let cust = new customer_info('Micheal Lambo', 49, "male");
  
  class account_details extends customer_info {
  
      constructor(account_no, account_name, initial_deposit){
          super(name, age);
          this.account_no = account_no;
          this.account_name = account_name;
          this.initial_deposit = initial_deposit;
      }
  
      deposit(){
  
      }
  
      withdrawal(){
  
      }
  
      balance(){
  
      }
  
      getCustomerAccount(){
        return super.getCustomerInfo();
      }
  
  }
  
  let cust_acct = new account_details();
  cust_acct.getCustomerAccount();
  </code></pre>