Refactor

backend/src/DataSource/DataSource.ts

@@ -5,12 +5,12 @@ type MessageCallback = (topic: string, payload: Buffer) => void
 
 // A DataSource should automatically reconnect if connection was broken
 interface DataSource<DataSourceOptions> {
+  topicSeparator: string
+  stateMachine: DataSourceStateMachine
   connect(options: DataSourceOptions): DataSourceStateMachine
   disconnect(): void
   onMessage(messageCallback: MessageCallback): void
   publish(msg: MqttMessage): void
-  topicSeparator: string
-  stateMachine: DataSourceStateMachine
 }
 
 export { DataSource, MessageCallback }