getPost method
- String postId
override
    Implementation
@override
TimelinePost? getPost(String postId) =>
    (posts.any((element) => element.id == postId))
        ? posts.firstWhere((element) => element.id == postId)
        : null;@override
TimelinePost? getPost(String postId) =>
    (posts.any((element) => element.id == postId))
        ? posts.firstWhere((element) => element.id == postId)
        : null;