mergeWith method
Merges value changes of this together with value changes of a List of
ValueListenables
so that when ever any of them changes the result of
mergeWith will change too.
final listenable1 = ValueNotifier<int>(0);
final listenable2 = ValueNotifier<int>(0);
final listenable3 = ValueNotifier<int>(0);
final listenable4 = ValueNotifier<int>(0);
listenable1.mergeWith([listenable2, listenable3, listenable4])
.listen((x, _) => print(x));
listenable2.value = 42;
listenable1.value = 43;
listenable4.value = 44;
listenable3.value = 45;
listenable1.value = 46;
```
Will print 42,43,44,45,46
Implementation
ValueListenable<T> mergeWith(
List<ValueListenable<T>> mergeWith,
) =>
MergingValueNotifiers<T>(this, mergeWith, this.value);