CurrentUserDefault doesn't work with AnonymousUser

[goliney]

I'm trying to use CurrentUserDefault with a field that can be null:

# model
class Package(models.Model):
    # User can be empty because we allow anonymous donations
    owner = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        null=True,
        blank=True,
    )

# serializer
class PackageSerializer(serializers.ModelSerializer):
    owner = serializers.HiddenField(default=serializers.CurrentUserDefault())

Everything works fine when a user is logged in. However, if a user is not authenticated I get this:

ValueError at /api/organizations/village/packages/
Cannot assign "<django.contrib.auth.models.AnonymousUser object at 0x7fc97ad6d940>": "Package.owner" must be a "User" instance.

Is there a reason why CurrentUserDefault doesn't work with anonymous users?

P.S. I know I can use this instead of CurrentUserDefault and it will work:

class AuthorizedUserOrNone:
    requires_context = True

    def __call__(self, serializer_field):
        user = serializer_field.context["request"].user
        if user.is_authenticated:
            return user

        return None

    def __repr__(self):
        return "%s()" % self.__class__.__name__

P.S.S. I duplicated this question to Stack Overflow

[hoonkii]

Why don't we modify CurrentUserDefault code like below?

class CurrentUserDefault:
    requires_context = True

    def __call__(self, serializer_field):
        user = serializer_field.context['request'].user
        if isinstance(user, AnonymousUser):
            return None
            
        return user

    def __repr__(self):
        return '%s()' % self.__class__.__name__