Getting NullPointer exception startActivityForResult

[SwenWallnoefer]

I am trying the following example:

android_intent.Intent()
      ..setAction('ACTION_PICK')
      ..setData(Uri.parse('content://contacts'))
      ..setType("vnd.android.cursor.dir/phone_v2")
      ..startActivityForResult().then((data) {
        print(data);
      }, onError: (e) => print(e));

It results in this exception:
D/AndroidRuntime(11988): Shutting down VM E/AndroidRuntime(11988): FATAL EXCEPTION: main E/AndroidRuntime(11988): Process: com.example.communication_test, PID: 11988 E/AndroidRuntime(11988): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=999, result=0, data=null} to activity {com.example.communication_test/com.example.communication_test.MainActivity}: java.lang.IllegalStateException: Reply already submitted E/AndroidRuntime(11988): at android.app.ActivityThread.deliverResults(ActivityThread.java:3574) E/AndroidRuntime(11988): at android.app.ActivityThread.handleSendResult(ActivityThread.java:3617) E/AndroidRuntime(11988): at android.app.ActivityThread.access$1300(ActivityThread.java:151) E/AndroidRuntime(11988): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1352) E/AndroidRuntime(11988): at android.os.Handler.dispatchMessage(Handler.java:102) E/AndroidRuntime(11988): at android.os.Looper.loop(Looper.java:135) E/AndroidRuntime(11988): at android.app.ActivityThread.main(ActivityThread.java:5254) E/AndroidRuntime(11988): at java.lang.reflect.Method.invoke(Native Method) E/AndroidRuntime(11988): at java.lang.reflect.Method.invoke(Method.java:372) E/AndroidRuntime(11988): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) E/AndroidRuntime(11988): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) E/AndroidRuntime(11988): Caused by: java.lang.IllegalStateException: Reply already submitted E/AndroidRuntime(11988): at io.flutter.embedding.engine.dart.DartMessenger$Reply.reply(DartMessenger.java:155) E/AndroidRuntime(11988): at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler$1.success(MethodChannel.java:238) E/AndroidRuntime(11988): at io.github.itzmeanjan.intent.IntentPlugin$onMethodCall$5.sendDocument(IntentPlugin.kt:180) E/AndroidRuntime(11988): at io.github.itzmeanjan.intent.IntentPlugin$onMethodCall$1.onActivityResult(IntentPlugin.kt:63) E/AndroidRuntime(11988): at io.flutter.embedding.engine.FlutterEngineConnectionRegistry$FlutterEngineActivityPluginBinding.onActivityResult(FlutterEngineConnectionRegistry.java:739) E/AndroidRuntime(11988): at io.flutter.embedding.engine.FlutterEngineConnectionRegistry.onActivityResult(FlutterEngineConnectionRegistry.java:426) E/AndroidRuntime(11988): at io.flutter.embedding.android.FlutterActivityAndFragmentDelegate.onActivityResult(FlutterActivityAndFragmentDelegate.java:668) E/AndroidRuntime(11988): at io.flutter.embedding.android.FlutterActivity.onActivityResult(FlutterActivity.java:618) E/AndroidRuntime(11988): at android.app.Activity.dispatchActivityResult(Activity.java:6192) E/AndroidRuntime(11988): at android.app.ActivityThread.deliverResults(ActivityThread.java:3570) E/AndroidRuntime(11988): ... 10 more

Can you tell me what i am doing wrong? I would like to receive some data back from an app which i launch with an intent.

Tank you!