# createFader method Null safety

dynamic createFader(

1. PlatformMediumModel android,
2. PlatformMediumModel iphone,
3. PlatformMediumModel tablet,
4. PlatformMediumModel macbook

)

## Implementation

    Future<FaderModel> createFader(
      PlatformMediumModel android,
      PlatformMediumModel iphone,
      PlatformMediumModel tablet,
      PlatformMediumModel macbook,
    ) async {
      var items = <ListedItemModel>[];
      items.add(ListedItemModel(
          documentID: "android",
          description: "Android",
          posSize: screen75(),
          image: android));
      items.add(ListedItemModel(
          documentID: "macbook",
          description: "Macbook",
          posSize: screen75(),
          image: macbook));
      items.add(ListedItemModel(
          documentID: "iphone",
          description: "iphone",
          posSize: screen75(),
          image: iphone));
      items.add(ListedItemModel(
          documentID: "tablet",
          description: "Tablet",
          posSize: screen75(),
          image: tablet));
      var model = FaderModel(
        documentID:
            constructDocumentId(uniqueId: uniqueId, documentId: componentId),
        description: "Welcome fader",
        animationMilliseconds: 1000,
        imageSeconds: 5,
        items: items,
        appId: app.documentID,
        conditions: StorageConditionsModel(
            privilegeLevelRequired:
                PrivilegeLevelRequiredSimple.noPrivilegeRequiredSimple),
      );
      await AbstractRepositorySingleton.singleton
          .faderRepository(app.documentID)!
          .add(model);
      return model;
    }