putOrFind<S>  method 
Implementation
S putOrFind<S>(InstanceBuilderCallback<S> dep, {String? tag}) {
  final key = _getKey(S, tag);
  if (_singl.containsKey(key)) {
    return _singl[key]!.getDependency() as S;
  } else {
    return GetInstance().put(dep(), tag: tag);
  }
}