Method _fireEvent

packages/core/data/observable/index.ts:424–443

(observers: Array<ListenerEntry>, data: T)

	}

	private static _fireEvent<T extends EventData>(observers: Array<ListenerEntry>, data: T): void {
		const length = observers.length;

		if (!length) {
			return;
		}

		if (length === 1) {
			const index = 0;
			this._handleListenerEntry<T>(observers[index], index, observers, data);
		} else {
			// This keeps a copy of observers list to ensure concurrency
			const observersCp = observers.slice();

			for (let i = 0; i < length; i++) {
				const entry = observersCp[i];
				this._handleListenerEntry<T>(entry, i, observers, data);
			}
		}
	}

	private static _handleListenerEntry<T extends EventData>(entry: ListenerEntry, index: number, observers: Array<ListenerEntry>, data: T): void {
		if (!entry) {