Function fire

tests/eventsource.js:700–708

(that, f, event)

  };

  var fire = function (that, f, event) {
    try {
      if (typeof f === "function") {
        f.call(that, event);
      }
    } catch (e) {
      throwError(e);
    }
  };

  function EventSourcePolyfill(url, options) {
    EventTarget.call(this);