func SetOn(on bool) {
	tracer.mu.Lock()
	tracer.on = on
	tracer.mu.Unlock()
}
func SetOn(on bool) {
	tracer.mu.Lock()
	tracer.on = on
	tracer.mu.Unlock()
}
func SetOn ( on bool ) { tracer . mu . Lock ( ) tracer . on = on tracer . mu . Unlock ( ) }
// SetOn sets tracing methods output active or inactive.
SetOn sets tracing methods output active or inactive .