Why does `DartObject.toMapValue` has `DartObject?` has key/value, but `DartObject.toListValue` has a non-nullable `DartObject`?

[rrousselGit]

Using analyzer, consider:

DartObject obj;
List<DartObject> list = obj.toListValue()!;
Set<DartObject> list = obj.toSetValue()!;
Map<DartObject?, DartObject?> map = obj.toMapValue()!;

It feels inconsistent that toListValue/toSetValuehave non-nullable elements, buttoMapValue` has nullable ones.

Could toMapValue be made to return Map<DartObject, DartObject>??

[rrousselGit]

Looking at the source, it looks like this is purely an API thing, and the implementation uses non-nullable objects

sdk/pkg/analyzer/lib/src/dart/constant/value.dart

Line 936 in ed54a42

Map<DartObjectImpl, DartObjectImpl>? toMapValue() {

[bwilkerson]

@kallentu This seems odd to me as well, but you've looked at this more recently than I have so perhaps you have more context.