src/vs/workbench/browser/parts/notifications/notificationsTelemetry.ts/NotificationsTelemetry/registerListeners
class NotificationsTelemetry:	private registerListeners(): void {
		this._register(this.notificationService.onDidAddNotification(notification => {
			const source = notification.source && typeof notification.source !== 'string' ? notification.source.id : notification.source;
			this.telemetryService.publicLog2<NotificationMetrics, NotificationMetricsClassification>('notification:show', notificationToMetrics(notification.message, source, !!notification.silent));
		}));

		this._register(this.notificationService.onDidRemoveNotification(notification => {
			const source = notification.source && typeof notification.source !== 'string' ? notification.source.id : notification.source;
			this.telemetryService.publicLog2<NotificationMetrics, NotificationMetricsClassification>('notification:close', notificationToMetrics(notification.message, source, !!notification.silent));
		}));
	}