title: Firebase with Robolectric
body: <p>I'm trying to write few tests for Firebase with Robolectric. But Firebase callbacks are never invoked. e.g.</p>
  
  <pre><code>@Test
  public void testFirebaseCallback() {
      Firebase firebase = new Firebase(Constants.FIREBASE_API_URL);
      firebase.child("custom_child").setValue("custom_value", new Firebase.CompletionListener() {
          @Override
          public void onComplete(FirebaseError firebaseError, Firebase firebase) {
              System.out.println("never goes here");
          }
      });
  
      sleep(10);
  }
  </code></pre>
  
  <p>My Robolectric config:</p>
  
  <pre><code>@RunWith(RobolectricGradleTestRunner.class)
  @Config(constants = BuildConfig.class, sdk = 16)
  </code></pre>
  
  <p>fyi. my calls didn't hit Firebase server without 5sec "sleep". With "sleep" - calls hit the server but callbacks are never invoked.</p>
  
  <p><a href="https://www.firebase.com" rel="nofollow">firebase</a></p>