try:
            pb_type = self._meta.fields[key].pb_type
            pb_value = getattr(self._pb, key)
            marshal = self._meta.marshal
            return marshal.to_python(pb_type, pb_value, absent=key not in self)
        except KeyError as ex:
>           raise AttributeError(str(ex))
E           AttributeError: 'object'

.nox/unit-3-7/lib/python3.7/site-packages/proto/message.py:615: AttributeError