invokeNavigation<T> method

@protected T? invokeNavigation<T>(T? nextCallback())

Implementation

@protected
T? invokeNavigation<T>(T? Function() nextCallback) {
  if (isNavigated) {
    debugPrint(
        "⚠️A navigation method invoked more than once on the same Navigator "
        "instance the widget can navigate.  ⚠️");
    debugPrint("⚠️We are letting only the first invocation through.  ⚠️");
    return null;
  }

  isNavigated = true;

  return nextCallback();
}