java.lang.NullPointerException in public void onStart() of UtteranceProgressListener

[ostpnk]

🐛 Bug Report

In (https://github.com/dlutton/flutter_tts/blob/3af42c523595176bf8475ae21865dd80a79c4bde/android/src/main/java/com/tundralabs/fluttertts/FlutterTtsPlugin.java) line 95 : this.onProgress(utteranceId, 0, utterances.get(utteranceId).length()); causes java.lang.NullPointerException after calling synthesizeToFile(..), because variable utterances only updated in method speak(..) - line 545

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Expected behavior

Reproduction steps

Configuration

Version: 0.1.x

Platform:

• [ ] :iphone: iOS
• [x] :robot: Android