def METHOD_NAME(self, property_name: str) -> Any:
    if self._linked_target:
        return getattr(self._linked_target, property_name)
    elif property_name in self._declared_properties:
        self._frozen_properties.add(property_name)
        return self._declared_properties[property_name]
    else:
        raise NotSpecifiedError(self.identifier, property_name)