code: function changePosition(el, index) {
  
              var HTMLElement = el.el;
              if (HTMLElement && HTMLElement.parentNode) {
  
                  var parentNode = HTMLElement.parentNode,
                      elGroup = el.elGroup,
                      size = elGroup.size,
                      target = elGroup.getKeyByIndex(index) || elGroup.getLast();
  
                  if (target !== HTMLElement) {
                      if (size - 1 >= index) {
                          parentNode.insertBefore(HTMLElement, target);
                      } else if (target.nextSibling !== null) {
                          parentNode.insertBefore(HTMLElement, target.nextSibling);
                      } else {
                          parentNode.appendChild(HTMLElement);
                      }
  
                      el.elGroup.changeIndex(HTMLElement, index);
                  }
              }
          }
docs: Changing position in nodeList  @method changePosition @param {dom.Element} @param {Int} index