anchor.diff:  /// If you want to obtain the current [state] from outside of [StateNotifier],
   /// consider using [addListener] instead.
   ///
  -/// All listeners added with [addListener] are called **immediatly** on addition
  +/// All listeners added with [addListener] are called **immediately** on addition
   /// with the current [state] as parameter, or whenever [state] changes.
   ///
   /// # The differences with `ValueNotifier`
  
positive.code: /// your custom [StateNotifier.state].
  typedef ErrorListener = void Function(dynamic error, StackTrace stackTrace);
  
  /// A funtion that allows obtaining other objects.
  ///
  /// This is usually equivalent to `Provider.of`, but with no dependency on Flutter
  ///
  
negative.code: 
    /// Subscribes to this object.
    ///
    /// The [listener] callback will be called immediately on addition and
    /// synchronously whenever [state] changes.
    ///
    /// To remove this [listener], call the function returned by [addListener]:
  