function cloneVNode (vnode, createElement) {
  const clonedChildren = vnode.children && vnode.children.map(vnode => cloneVNode(vnode, createElement))
  const cloned = createElement(vnode.tag, vnode.data, clonedChildren)
  cloned.text = vnode.text
  cloned.isComment = vnode.isComment
  cloned.componentOptions = vnode.componentOptions
  cloned.fnOptions = vnode.fnOptions
  cloned.fnContext = vnode.fnContext
  cloned.elm = vnode.elm
  cloned.context = vnode.context
  cloned.ns = vnode.ns
  cloned.isStatic = vnode.isStatic
  cloned.key = vnode.key
  cloned.data = vnode.data
  return cloned
}
Clones a single VNode
@param {Vue.VNode} vnodes VNode to be cloned
@param {Function} createElement Render function
@returns {Vue.VNode} Cloned VNodes