src/vs/platform/launch/electron-main/launchMainService.ts/LaunchMainService/start
class LaunchMainService:	async start(args: NativeParsedArgs, userEnv: IProcessEnvironment): Promise<void> {
		this.logService.trace('Received data from other instance: ', args, userEnv);

		// macOS: Electron > 7.x changed its behaviour to not
		// bring the application to the foreground when a window
		// is focused programmatically. Only via `app.focus` and
		// the option `steal: true` can you get the previous
		// behaviour back. The only reason to use this option is
		// when a window is getting focused while the application
		// is not in the foreground and since we got instructed
		// to open a new window from another instance, we ensure
		// that the app has focus.
		if (isMacintosh) {
			app.focus({ steal: true });
		}

		// Check early for open-url which is handled in URL service
		const urlsToOpen = this.parseOpenUrl(args);
		if (urlsToOpen.length) {
			let whenWindowReady: Promise<unknown> = Promise.resolve();

			// Create a window if there is none
			if (this.windowsMainService.getWindowCount() === 0) {
				const window = this.windowsMainService.openEmptyWindow({ context: OpenContext.DESKTOP })[0];
				whenWindowReady = window.ready();
			}

			// Make sure a window is open, ready to receive the url event
			whenWindowReady.then(() => {
				for (const { uri, url } of urlsToOpen) {
					this.urlService.open(uri, { originalUrl: url });
				}
			});
		}

		// Otherwise handle in windows service
		else {
			return this.startOpenWindow(args, userEnv);
		}
	}