def storage(self, provider='osfstorage'):
        """Return storage `provider`."""
        stores = self._json(self._get(self._storages_url), 200)
        stores = stores['data']
        for store in stores:
            provides = self._get_attribute(store, 'attributes', 'provider')
            if provides == provider:
                return Storage(store, self.session)

        raise RuntimeError("Project has no storage "
                           "provider '{}'".format(provider))
Return storage `provider`.