code: @Override
      public XValue call(Scope scope) {
          Elements context = new Elements();
          for (Element el:scope.context()){
              context.addAll(el.children());
              String  txt = el.ownText();
              if (StringUtils.isNotBlank(txt)){
                  Element et = new Element("");
                  et.appendText(txt);
                  context.add(et);
              }
          }
          return XValue.create(context);
      }
docs: 函数具体逻辑
  
  @param scope 上下文
  @return 计算好的节点