Why not the same as deleteAllTasks()？

https://github.com/googlesamples/android-architecture/blob/6419d4c523b67d020120fc400ed5a7372e5615f2/todoapp/app/src/main/java/com/example/android/architecture/blueprints/todoapp/data/source/TasksRepository.java#L299

In line 288, it judges the Map is null or not. Then new a map? If line 299 not like this, NullPointException will be trigged.

Start with TasksRepository.java at the referenced lines 288-299 and compare that path with deleteAllTasks(). Check whether the map can be null at line 299 and confirm the expected behavior by reviewing the surrounding repository logic; done means the null-handling difference and any resulting NullPointerException are addressed.

Written by the indexing model from the issue text.