title: Thread of Dispatchers.IO coroutine
body: <p>I'm learning coroutines in Android. I have the following code:</p>
  
  <pre><code>private val scope = CoroutineScope(Dispatchers.Main + job)
  
  operator fun invoke(token: String, callback: TaskCallback) {
      scope.launch {
          withContext(Dispatchers.IO) { userDataSource.saveApiToken(token) }
          callback.onCompleted()
      }
  }
  </code></pre>
  
  <p>I expected that <code>userDataSource.saveApiToken(token)</code> will be called from separate thread, but it runs on the main thread (Looper.myLooper() == Looper.getMainLooper() returns true inside the method). 
  What can be the cause? [my mistake]</p>
  
  <p>I'm using Kotlin plugin version: 1.3.11-release-Studio3.2-1 and the following dependencies: kotlinx-coroutines-core:1.0.1 and kotlinx-coroutines-android:1.0.1</p>