interface instead of type

dist/main.js

@@ -11,6 +11,7 @@ class Dispatcher {
     exec() {
         log.info("Dispatcher starting");
         this._mqttClient.exec();
+        log.info("Dispatcher running");
     }
 }
 const dispatcher = new Dispatcher();

dist/mqttclient.js

@@ -26,6 +26,9 @@ class MqttClient {
             for (let topicHandler of this._topicHandlers) {
                 if (this.topicMatch(topicHandler.topic, topic)) {
                     log.info(`received topic ${topic} matches registered topic ${topicHandler.topic}`);
+                    if (topicHandler.callback != null) {
+                        topicHandler.callback(payload);
+                    }
                 }
             }
         });