es6 async await fetch

es6 async await fetch

class API {
  constructor(url){
    this.BASE_URL = url;
  }

  async post(url, data) {
    const response = await fetch(this.BASE_URL + url, {
      method: "POST",
      headers: {'Content-Type': 'application/json'},
      body: JSON.stringify(data)
    });

    if (!(response.status >= 200 && response.status < 300)) {  
       console.log(response.statusText);  
       return null;
    }  

    const json = await response.json();
    return json;
  }
}

const api = new API('http://localhost:8192');

class Z {
  constructor() {
    this.init();
    window.zzz = this;
  }

  async init () {
    this.id = await api.post('/batch/wizard/', {action:"CREATE"});
  }
}

const z = new Z();