src/vs/platform/native/electron-main/nativeHostMainService.ts/NativeHostMainService/getActiveWindowId
class NativeHostMainService:	async getActiveWindowId(windowId: number | undefined): Promise<number | undefined> {
		const activeWindow = BrowserWindow.getFocusedWindow() || this.windowsMainService.getLastActiveWindow();
		if (activeWindow) {
			return activeWindow.id;
		}

		return undefined;
	}