driver/sqltrace/sqltrace.go
func On() bool {
	tracer.mu.RLock()
	on := tracer.on
	tracer.mu.RUnlock()
	return on
}
func On() bool {
	tracer.mu.RLock()
	on := tracer.on
	tracer.mu.RUnlock()
	return on
}
// On returns if tracing methods output is active.