define([],function(){"use strict";function fallback(urls){var i=0;!function createIframe(){var frame=document.createElement("iframe");frame.style.display="none",frame.src=urls[i++],document.documentElement.appendChild(frame);var interval=setInterval(function(){"complete"===frame.contentWindow.document.readyState&&(clearInterval(interval),setTimeout(function(){frame.parentNode.removeChild(frame)},1e3),i<urls.length&&createIframe())},100)}()}function isFirefox(){return/Firefox\//i.test(navigator.userAgent)}function sameDomain(url){var a=document.createElement("a");return a.href=url,location.hostname===a.hostname&&location.protocol===a.protocol}function download(url){var a=document.createElement("a");a.download="",a.href=url,a.dispatchEvent(new MouseEvent("click"))}return function(urls){if(!urls)throw new Error("`urls` required");if("undefined"==typeof document.createElement("a").download)return fallback(urls);var delay=0;urls.forEach(function(url){return isFirefox()&&!sameDomain(url)?setTimeout(download.bind(null,url),100*++delay):void download(url)})}});