Dart generic test

class MyGenericClass<TKey, TValue> {
  Map<TKey, TValue> map;
  MyGenericClass() {
    this.map = new Map<TKey, TValue>();
  }

  myAdd(TKey key, TKey/*TValue*/ value) {
    this.map[key] = value; // Warning. Great!
    return this;
  }

  myGet(TKey key) => this.map[key];
}

main() {
  var test = new MyGenericClass<int, int>();
  test.myAdd(10, 20);
  print('Result is not ${test.myGet(10) - 1}');
}