dart extending list

import 'dart:collection';

class MyCustomList<E> extends ListBase<E> {
  final List<E> l = [];
  
  set length(int newLength) {
    l.length = newLength;
  }

  int get length => l.length;

  E operator [](int index) => l[index];

  void operator []=(int index, E value) {
    l[index] = value;
  }
}