src/vs/workbench/common/notifications.ts/NotificationsModel/showStatusMessage
class NotificationsModel:	showStatusMessage(message: NotificationMessage, options?: IStatusMessageOptions): IDisposable {
		const item = StatusMessageViewItem.create(message, options);
		if (!item) {
			return Disposable.None;
		}

		// Remember as current status message and fire events
		this._statusMessage = item;
		this._onDidChangeStatusMessage.fire({ kind: StatusMessageChangeType.ADD, item });

		return toDisposable(() => {

			// Only reset status message if the item is still the one we had remembered
			if (this._statusMessage === item) {
				this._statusMessage = undefined;
				this._onDidChangeStatusMessage.fire({ kind: StatusMessageChangeType.REMOVE, item });
			}
		});
	}