Error deserializing

When receiving JSON:
[ { "id": 1, "name": "Test", "schedule": { "slots": [ [], [], [], [], [], [], [ { "time_from": "10:30:00", "time_to": "15:45:00" } ] ] } } ]

I get an error after the response:
DioError [unknown]: null I/flutter (19668): │ Error: Deserializing '[{id: 2, name: Test, email: test@gmail.com...' to 'BuiltList' failed due to: Deserializing '[id, 2, name, Test, email, test@gmail.com...' to 'OverviewPlace' failed due to: Deserializing '[slots, [[], [{time_from: 07:00:00, time_to: 14:00:00}, {time_from: 15:00:00,...' to 'Schedule?' failed due to: Deserializing '[[], [{time_from: 07:00:00, time_to: 14:00:00}, {time_from: 15:00:00, time_to...' to 'BuiltList<BuiltList>' failed due to: Deserializing '[]' to 'BuiltList' failed due to: Bad state: No builder factory for BuiltList. Fix by adding one, see SerializersBuilder.addBuilderFactory.

It was solved by adding the code to the serializers.dart file:
..addBuilderFactory( const FullType(BuiltList, [FullType(TimeSlot)]), () => ListBuilder(), )

The issue names the generated serializers.dart file and shows a nested empty-list deserialization failure. Start by reproducing the response with empty schedule slots and inspecting the generated serializer registrations. Done means the generated client deserializes the nested BuiltList without manually editing serializers.dart.