@Override
  public boolean equals(Object obj) {
    if (this == obj)
      return true;
    if (obj == null)
      return false;
    if (getClass() != obj.getClass())
      return false;
    Order other = (Order) obj;
    if (orderNumber == null) {
      if (other.orderNumber != null)
        return false;
    } else if (!orderNumber.equals(other.orderNumber))
      return false;
    return true;
  }