code: private static List<String> getElementsId(Document document) {
          List<String> result = new ArrayList<String>();
  
          List<Element> elementList = getElements(document);
  
          result = getElementsId(elementList);
  
          return result;
      }
docs: Reads XML document and returns it content as list of query names
  
  @param document document which would be read
  @return list of queries names