def prov(self):
        """
        :return: This bundle's provenance
        :rtype: :py:class:`prov.model.ProvDocument`
        """
        if not self._prov:
            self._prov = self._api.get_bundle(self._document.id, self._id)

        return self._prov
:return: This bundle's provenance
        :rtype: :py:class:`prov.model.ProvDocument`