private void fireCurrentItemChanged(@Nullable LookupElement oldItem, @Nullable LookupElement currentItem) {
    if (oldItem != currentItem && !myListeners.isEmpty()) {
      LookupEvent event = new LookupEvent(this, currentItem, (char)0);
      for (LookupListener listener : myListeners) {
        listener.currentItemChanged(event);
      }
    }
    myPreview.updatePreview(currentItem);
  }
private void fireCurrentItemChanged(@Nullable LookupElement oldItem, @Nullable LookupElement currentItem)