gistfile1.py

    def copy(self, **kwargs):
        kwargs['base_image_name'] = kwargs['base_image_name'] or self.base_image_name
        kwargs['format']          = kwargs['format'] or self.format
        kwargs['size']            = kwargs['size'] or self.size
        kwargs['is_temp']         = kwargs['is_temp'] or self.is_temp
        
        newimage = Image(**kwargs)