title: Android: Firebase ChildEventListener() not working
body: <p>I am working in my app with Firebase and I tried to use onChildAdded() callback but I think I am doing something wrong because I get no response.</p>
  
  <pre><code>/**
   * Constructor
   */
  private FirebaseManager(Context context) {
      Firebase.setAndroidContext(context);
      Firebase.getDefaultConfig().setPersistenceEnabled(true);
      mFirebaseRef = new Firebase(FIREBASE_URL);
  }
  </code></pre>
  
  <hr>
  
  <pre><code>public void checkUsers() {
      Firebase checkRef = mFirebaseRef.child("/data/users/");
      // Also tried 
      // Firebase checkRef = mFirebaseRef.child("data").child("users");
      checkRef.addChildEventListener(new ChildEventListener() {
          @Override
          public void onChildAdded(DataSnapshot dataSnapshot, String s) {
              Log.d(TAG,"New child added");
          }
  
          @Override
          public void onChildChanged(DataSnapshot dataSnapshot, String s) {
  
          }
  
          @Override
          public void onChildRemoved(DataSnapshot dataSnapshot) {
  
          }
  
          @Override
          public void onChildMoved(DataSnapshot dataSnapshot, String s) {
  
          }
  
          @Override
          public void onCancelled(FirebaseError firebaseError) {
  
          }
  
  
      });
  }
  </code></pre>
  
  <p>In onCreate() of my MainActivity I authenticate the user and the call checkUsers(). After that I manually add a new user in database. But I get nothing in log.
  This is the json structure:</p>
  
  <p><a href="https://i.stack.imgur.com/RIkQ4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RIkQ4.png" alt="enter image description here"></a></p>
  
  <p><strong>What am I doing wrong?</strong></p>