function delete_resources_by_tag($tag, $options = array())
{
$resource_type = \Cloudinary::option_get($options, "resource_type", "image");
$uri = array("resources", $resource_type, "tags", $tag);
return $this->call_api("delete", $uri, $this->only($options, array("keep_original", "next_cursor", "invalidate")), $options);
}