SOURCE

class myFetch{
    constructor(count){
        this.sumCount = count;
        this.resCount = 0;
    }

    request(method, api){
        if(method === 'POST'){
            this.myPost(api)
        }
        if(method === 'GET'){

        }
    }

    myPost(url){
        this.myFecth(url)
    }

    myFecth(url){
        if(this.resCount < this.sumCount){
            fetch(url).then(res=>{
                if(res.errcode === 200){
                    console.log('success')
                }
            }).catch(err=>{
                this.resCount++;
                if(this.resCount < this.sumCount){
                    this.myFecth(url)
                }
            })
        }
    }  
}