code: protected List<VariableExtractor> getVariableExtractors(Element element) {
          List<VariableExtractor> variableExtractors = new ArrayList<>();
  
          parseExtractHeaderElements(element, variableExtractors);
  
          Element extractElement = DomUtils.getChildElementByTagName(element, "extract");
          if (extractElement != null) {
              Map<String, String> extractFromPath = new HashMap<>();
  
              List<Element> messageValueElements = DomUtils.getChildElementsByTagName(extractElement, "message");
              messageValueElements.addAll(DomUtils.getChildElementsByTagName(extractElement, "body"));
              VariableExtractorParserUtil.parseMessageElement(messageValueElements, extractFromPath);
  
              if (!CollectionUtils.isEmpty(extractFromPath)) {
                  VariableExtractorParserUtil.addPayloadVariableExtractors(element, variableExtractors, extractFromPath);
              }
          }
          return variableExtractors;
      }
docs: Constructs a list of variable extractors.
  @param element
  @return