Doesn't work with nullable nested

[ADR-007]

Hi!

I found a problem with serializers like:

class MySerializer(...):
    my_nested = MyDataclassSerializer(allow_null=True, required=False)

The fix:

def create(self, validated_data):
    if validated_data is None:
        return None

    dataclass_type = self.get_dataclass_type()
    return dataclass_type(**self.instantiate_data_dictionaries(validated_data))

[oxan]

Fixed!