gcsweb/cmd/gcsweb/gcsweb.go
func (tl txnLogger) Printf(fmt string, args ...interface{}) {
	args = append([]interface{}{tl.nonce}, args...)
	log.Printf("[txn-%s] "+fmt, args...)
}
func (tl txnLogger) Printf(fmt string, args ...interface{}) {
	args = append([]interface{}{tl.nonce}, args...)
	log.Printf("[txn-%s] "+fmt, args...)
}
// Printf logs a formatted line to the logging output.