js 封装一个异步任务函数

// 异步任务 封装
// 1,定义函数 
// 2，使用核心api(queueMicrotask,MutationObserver,setTimeout)
function runAsynctask (callback){
   if(typeof queueMicrotask ==="function" ){
       queueMicrotask(callback)
   }else if( typeof MutationObserver ==="function" ){
       const obs = new MutationObserver(callback)
       const divNode =document.createElement('div')
       obs.observe(divNode,{childList:true })
       divNode.innerHTML = 'sss'
   }else{
       setTimeout(callback,0)
   }
}