@Override
 public void setPrimaryItem(ViewGroup container, int position, Object object) {
   super.setPrimaryItem(container, position, object);
   ArticleDetailFragment fragment = (ArticleDetailFragment) object;
   if (fragment != null) {
     mSelectedItemUpButtonFloor = fragment.getUpButtonFloor();
     updateUpButtonPosition();
   }
 }
 @Override
 public void setPrimaryItem(ViewGroup container, int position, Object object) {
   super.setPrimaryItem(container, position, object);
 }
 @Override
 public void setPrimaryItem(ViewGroup container, int position, Object object) {
   super.setPrimaryItem(container, position, object);
   ArticleDetailFragment fragment = (ArticleDetailFragment) object;
   if (fragment != null) {}
 }
 @Override
 public void destroyItem(ViewGroup container, int position, Object object) {
   registeredFragments.remove(position);
   super.destroyItem(container, position, object);
 }
 @Override
 public void setPrimaryItem(ViewGroup container, int position, Object object) {
   super.setPrimaryItem(container, position, object);
   mCurrentDetailsFragment = (ArticleDetailFragment) object;
 }