_nextNode () {
    let nextNode = null
    const dom = this.getDom()
    if (dom && dom.parentNode) {
      // find the previous field
      let nextDom = dom
      do {
        nextDom = nextDom.nextSibling
        nextNode = Node.getNodeFromTarget(nextDom)
      }
      while (nextDom && nextNode && (nextNode instanceof AppendNode && !nextNode.isVisible()))
    }

    return nextNode
  }
Get the next rendered node
@return {Node | null} nextNode
@private