title: UICollectionView cellForItemAtIndexPath method is not getting called
body: <p><code>cellForItemAtIndexPath</code> is not called. Everything is normal I think
  what is problem?</p>
  
  <pre><code>-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
  {
      return 1;
  }
  
  -(NSInteger) collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
  {
      return 10;
  }
  
  - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
  {
      CollectionViewCell *cell=(UICollectionView *)[collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];
  
      cell.titleText.text=@"test";
  
      return cell;
  }
  </code></pre>