Array.from polyfill (see also https://github.com/mathiasbynens/Array.from )
/**
* @license MIT, GPL, do whatever you want
* @requires polyfill: Array.prototype.slice fix {@link https://gist.github.com/brettz9/6093105}
*/
if (!Array.from) {
Array.from = function (object) {
'use strict';
return [].slice.call(object);
};
}