putIfAbsent method
Performs a Map.putIfAbsent and returns its return value.
Implementation
T putIfAbsent(
E key,
T value, {
bool doNotifyListeners = true,
}) {
final returnValue = _value.putIfAbsent(key, () => value);
if (doNotifyListeners) {
notifyListeners();
}
return returnValue;
}