For this first task, create a new private method named normalizeDiscountCode. It should take the discount code that is p

public class Order {
  private String itemName;
  private int priceInCents;
  private String discountCode;

  public Order(String itemName, int priceInCents) {
    this.itemName = itemName;
    this.priceInCents = priceInCents;
  }
  private boolean normalizeDiscountCode(String discountCode){
    boolean letter = false;
    if(! Character.isLetter(letter){
      throw new IllegalAgumentException("Letter is required")
    }
       letter = Character.toUpperCase(letter);
       return letter;
  }

  public String getItemName() {
    return itemName;
  }

  public int getPriceInCents() {
    return priceInCents;
  }

  public String getDiscountCode() {
    return discountCode;
  }

  public String applyDiscountCode(String discountCode) {
      discountCode = normalizeDiscountCode(discountCode);
      boolean isLetter = Character.indexOf(discountCode);
      if(isLetter){
        itemName += discountCode;
      }else{
        priceCent = discountCode;
      }
      return isLetter;

  }
}

public class Example {

  public static void main(String[] args) {
    // This is here just for example use cases.

    Order order = new Order(
            "Yoda PEZ Dispenser",
            600);

    // These are valid.  They are letters and the $ character only
    order.applyDiscountCode("abc");
    order.getDiscountCode(); // ABC

    order.applyDiscountCode("$ale");
    order.getDiscountCode(); // $ALE


    try {
      // This will throw an exception because it contains numbers
      order.applyDiscountCode("ABC123");
    } catch (IllegalArgumentException iae) {
      System.out.println(iae.getMessage());  // Prints "Invalid discount code"
    }
    try {
      // This will throw as well, because it contains a symbol.
      order.applyDiscountCode("w@w");
    }catch (IllegalArgumentException iae) {
      System.out.println(iae.getMessage());  // Prints "Invalid discount code"
    }

  }
}