rewrite checkpoint

vendor/github.com/guelfey/go.dbus/_examples/introspect.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"encoding/json"
+	"github.com/guelfey/go.dbus"
+	"github.com/guelfey/go.dbus/introspect"
+	"os"
+)
+
+func main() {
+	conn, err := dbus.SessionBus()
+	if err != nil {
+		panic(err)
+	}
+	node, err := introspect.Call(conn.Object("org.freedesktop.DBus", "/org/freedesktop/DBus"))
+	if err != nil {
+		panic(err)
+	}
+	data, _ := json.MarshalIndent(node, "", "    ")
+	os.Stdout.Write(data)
+}