def _uuid(self):
        """
        An instance-specific UUID, to avoid multiple deserializations of
        a given instance.

        Note this is lazily-generated, for performance reasons.
        """
        u = self.__uuid
        if u is None:
            u = str(uuid.uuid1())
            self._set_uuid(u)
        return u

        An instance-specific UUID, to avoid multiple deserializations of
        a given instance.

        Note this is lazily-generated, for performance reasons.
        
numba/core/extending.py