function CustomEvent (event, params) {
		params = params || {bubbles : false, cancelable : false, detail: undefined};
		var evt = document.createEvent('CustomEvent');
		evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail);
		return evt;
	}
Change the function to execute on unhandled rejection
@param {function} fn Function to execute on unhandled rejection
@deprecated