prefer_void_to_null
Unnecessary use of the type 'Null'.
Description
#
The analyzer produces this diagnostic when Null is used in a location
where void would be a valid choice.
Example
#
The following code produces this diagnostic because the function f is
declared to return null (at some future time):
dart
Future<Null> f() async {}
Common fixes
#Replace the use of Null with a use of void:
dart
Future<void> f() async {}