def types(self):
        """A tuple containing the value types for this Slot.

        The Python equivalent of the CLIPS deftemplate-slot-types function.

        """
        data = clips.data.DataObject(self._env)

        lib.EnvDeftemplateSlotTypes(
            self._env, self._tpl, self._name, data.byref)

        return tuple(data.value) if isinstance(data.value, list) else ()