title: Flutter plugin: "Methods marked with @UiThread must be executed on the main thread."
body: <p>I am creating Flutter plugin. There are few channels on which I am sending the callbacks from Android to Flutter. Situation is that I am listening for some events which are triggered in OTHER thread than main UI thread.</p>
  
  <p>After recent Flutter update I starting to receive such an error</p>
  
  <pre><code>E/AndroidRuntime( 9400): FATAL EXCEPTION:  STARTING
  E/AndroidRuntime( 9400): Process: com.northernbitcoin.coinyacapp, PID: 9400
  E/AndroidRuntime( 9400): java.lang.RuntimeException: Methods marked with @UiThread must be executed on the main thread. Current thread:  STARTING
  E/AndroidRuntime( 9400):    at io.flutter.embedding.engine.FlutterJNI.ensureRunningOnMainThread(FlutterJNI.java:794)
  E/AndroidRuntime( 9400):    at io.flutter.embedding.engine.FlutterJNI.dispatchPlatformMessage(FlutterJNI.java:684)
  E/AndroidRuntime( 9400):    at io.flutter.embedding.engine.dart.DartMessenger.send(DartMessenger.java:80)
  E/AndroidRuntime( 9400):    at io.flutter.embedding.engine.dart.DartExecutor.send(DartExecutor.java:174)
  E/AndroidRuntime( 9400):    at io.flutter.view.FlutterNativeView.send(FlutterNativeView.java:144)
  E/AndroidRuntime( 9400):    at io.flutter.plugin.common.EventChannel$IncomingStreamRequestHandler$EventSinkImplementation.success(EventChannel.java:226)
  ...
  </code></pre>
  
  <p>Only information I found is here
  <a href="https://github.com/flutter/flutter/issues/34993" rel="noreferrer">https://github.com/flutter/flutter/issues/34993</a></p>
  
  <p>Yes, there are a solution here
  <a href="https://github.com/flutter/flutter/issues/34993#issue-459900986" rel="noreferrer">https://github.com/flutter/flutter/issues/34993#issue-459900986</a></p>
  
  <p>But it looks like too overhead for me, because I dont't want to create new <code>handler</code> for each my event</p>
  
  <p>Is there any other solutions?</p>