(() => { if (typeof window.CustomEvent === 'function') { return; } function CustomEvent(event, params) { params = params || { bubbles: false, cancelable: false, detail: null }; const evt = document.createEvent('CustomEvent'); evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail); return evt; } CustomEvent.prototype = window.CustomEvent?.prototype || window.Event.prototype; window.CustomEvent = CustomEvent; })();