func printJSON(v interface{}) {
	w := json.NewEncoder(os.Stdout)
	w.SetIndent("", "\t")
	err := w.Encode(v)
	if err != nil {
		panic(err)
	}
}
func printJSON(v interface{}) {
	w := json.NewEncoder(os.Stdout)
	w.SetIndent("", "\t")
	err := w.Encode(v)
	if err != nil {
		panic(err)
	}
}
// printJSON prints v as JSON encoded with indent to stdout. It panics on any error.