Define an empty Shutdown function on base daemon

daemon.go

@@ -164,6 +164,8 @@ func (d *BaseDaemon) Logf(format string, v ...interface{}) {
 	d.logger.Printf(format, v...)
 }
 
+func (d *BaseDaemon) Shutdown() {}
+
 // String returns the name of the Deamon unerlying struct.
 func (d *BaseDaemon) String() string {
 	if d.name == "" {

example/daemons/number_printer.go

@@ -22,9 +22,6 @@ func (n *NumberPrinter) Startup() {
 	n.SystemProcess("Random Number Generator", n.generateNumbers)
 }
 
-// Shutdown is empty due to the lack of cleanup.
-func (n *NumberPrinter) Shutdown() {}
-
 func (n *NumberPrinter) generateNumbers() {
 	for n.Continue() {
 		if rand.Intn(10) == 0 {

example/daemons/price_consumer.go

@@ -24,6 +24,3 @@ func (p *PriceConsumer) Startup() {
 	})
 	p.LimitRate(5, time.Second)
 }
-
-// Shutdown is empty because PriceConsumer requires no cleanup upon exiting.
-func (p *PriceConsumer) Shutdown() {}