Non-final field referenced in 'hashCode()'

class Drink {
  String name;
  Drink(String name) { this.name = name; }
  @Override public int hashCode() {
    return Objects.hash(name); //warning
  }
}
...
  Drink coffee = new Drink("Coffee");
  priceMap.put(coffee, 10.0);
  coffee.name = "Tea";
  double coffeePrice = priceMap.get(coffee); //not found

class Drink {
  final String name;
  ...
}