I want to code my own Map class. MapBase and MapMixin have similar documentations. Which one should I use to code my own Map class? And why?

I understand MapBase has more functions because it implements MapMixin. However, the functions in MapBase don't seem to be important because all of its functions are static.

...
/// A basic `Map` class can be implemented by extending this class and
/// implementing `keys`, `operator[]`, `operator[]=`, `remove` and `clear`.
/// The remaining operations are implemented in terms of these five.
...
abstract class MapBase<K, V> extends MapMixin<K, V> {

...
/// A basic `Map` class can be implemented by mixin in this class and
/// implementing `keys`, `operator[]`, `operator[]=`, `remove` and `clear`.
/// The remaining operations are implemented in terms of these five.
...
abstract class MapMixin<K, V> implements Map<K, V> {

CodePudding user response：

It does not really matter. The advantage with the mixin is that you can include multiple mixins in your class where you can only extend from one class.