def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def test_reserve_unreserve_volume(self):
        """Test reserving and unreserving volume"""
        # Mark volume as reserved.
        self.volumes_client.reserve_volume(self.volume['id'])
        # To get the volume info
        body = self.volumes_client.show_volume(self.volume['id'])['volume']
        self.assertIn('attaching', body['status'])
        # Unmark volume as reserved.
        self.volumes_client.unreserve_volume(self.volume['id'])
        # To get the volume info
        body = self.volumes_client.show_volume(self.volume['id'])['volume']
        self.assertIn('available', body['status'])