private void readExternalCollection(Element parentElement, Collection<? super String> collection, String collectionName, String itemName) {
    Element child = parentElement.getChild(getTagName());
    if (child != null) {
      collection.clear();
      Element item = child.getChild(collectionName);
      if (item != null) {
        for (Element element : item.getChildren(itemName)) {
          collection.add(element.getAttributeValue(COLLECTION_ITEM_ATTRIBUTE));
        }
      }
    }
  }
private void readExternalCollection(Element parentElement, Collection<? super String> collection, String collectionName, String itemName)