Method attachEvent

packages/base/src/EventProvider.ts:8–20

(eventName: string, fnFunction: (param: EventListenerParam) => EventListenerReturn)

	}

	attachEvent(eventName: string, fnFunction: (param: EventListenerParam) => EventListenerReturn) {
		const eventRegistry = this._eventRegistry;
		const eventListeners = eventRegistry.get(eventName);

		if (!Array.isArray(eventListeners)) {
			eventRegistry.set(eventName, [fnFunction]);
			return;
		}

		if (!eventListeners.includes(fnFunction)) {
			eventListeners.push(fnFunction);
		}
	}

	detachEvent(eventName: string, fnFunction: (param: EventListenerParam) => EventListenerReturn) {
		const eventRegistry = this._eventRegistry;