/**
  * Add an item of type BaseField to the field collection
  *
  * @param BaseField $objItem
  */
 public function addItem(BaseField $objItem)
 {
     $this->items[] = $objItem;
     end($this->items);
     $key = key($this->items);
     $this->index[$key] = $objItem->get('colName');
 }