Null safety update

Hello
Love your videos and thank you for putting in so much effort.
I have 2 questions
1) Will you update the code for null safety?
2) Don't you have to initialize all providers under MultiProvider?
When trying to use your code, it wants to me initialize FireStoreService provider as well, which i try to do like this
Provider
(
create: (context) => FirestoreService(uid: UserData().uid),
),
However, since UserData().uid is null at that point, i don't think this will work, even with assert(uid.isNotEmpty)

Begin with the MultiProvider setup and FirestoreService usage described in the issue; inspect how UserData().uid is obtained before provider creation. Review the repository's Dart code for the requested null-safety update and determine how provider initialization should behave when the user id is null; done means the questions are resolved in working code.

Written by the indexing model from the issue text.