code: function base64ToHex(str) {
          for (var i = 0, bin = atob(str.replace(/[ \r\n]+$/, "")), hex = []; i < bin.length; ++i) {
              var tmp = bin.charCodeAt(i).toString(16);
              if (tmp.length === 1) tmp = "0" + tmp;
              hex[hex.length] = tmp;
          }
          return hex.join(" ");
      }
docs: base64ToHex
  @private