backend.js

'use strict';

window.backend = (function () {
  var URL_DOWNLOAD = 'https://js.dump.academy/code-and-magick/data';
  var URL_UPLOAD = 'https://js.dump.academy/code-and-magick';

  var xhr = new XMLHttpRequest();
  xhr.responseType = 'json';

  return {
    load: function (onLoad, onError) {

    },
    save: function (data, onLoad, onError) {

    }
  };
})();