Changed example sources according to the basic documentation example

examples/random/main.go

@@ -18,6 +18,7 @@ package main
 
 import (
 	"flag"
+	"log"
 	"math"
 	"math/rand"
 	"net/http"
@@ -99,5 +100,5 @@ func main() {
 
 	// Expose the registered metrics via HTTP.
 	http.Handle("/metrics", prometheus.Handler())
-	http.ListenAndServe(*addr, nil)
+	log.Fatal(http.ListenAndServe(*addr, nil))
 }

examples/simple/main.go

@@ -16,6 +16,7 @@ package main
 
 import (
 	"flag"
+	"log"
 	"net/http"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -26,5 +27,5 @@ var addr = flag.String("listen-address", ":8080", "The address to listen on for
 func main() {
 	flag.Parse()
 	http.Handle("/metrics", prometheus.Handler())
-	http.ListenAndServe(*addr, nil)
+	log.Fatal(http.ListenAndServe(*addr, nil))
 }