arthuredelstein

let locales = ["ar", "de", /*"en-US",*/ "es-ES", "fa", "fr", "ja", "it",
               "ko", "nl", "pl", "pt-BR", /*"ru",*/ "tr", "vi", "zh-CN"];

let listenOnce = (element, event, useCapture) => {
  return new Promise(function (resolve, reject) {
    let onEvent = function (ev) {
      element.removeEventListener(event, onEvent, useCapture);
      resolve(ev);
    };
    element.addEventListener(event, onEvent, useCapture);