title: Robolectric test to check if a SnackBar is shown?
body: <p>I am calling the following code in my app:</p>
  
  <pre><code>Snackbar.make(this, R.string.empty_task_message, Snackbar.LENGTH_LONG)
      .show()
  </code></pre>
  
  <p>How can I assert that this was indeed called, inside my Robolectric test?</p>
  
  <p>I was thinking of something like traversing the view hierarchy and searching for a <code>Snackbar</code> instance and checking if the view is visible.</p>
  
  <p>This looks like a long standing problem in Robolectric.</p>