src/vs/platform/url/common/urlIpc.ts/URLHandlerRouter/routeCall
class URLHandlerRouter:	async routeCall(hub: IConnectionHub<string>, command: string, arg?: any, cancellationToken?: CancellationToken): Promise<Client<string>> {
		if (command !== 'handleURL') {
			throw new Error(`Call not found: ${command}`);
		}

		if (arg) {
			const uri = URI.revive(arg);

			if (uri && uri.query) {
				const match = /\bwindowId=(\d+)/.exec(uri.query);

				if (match) {
					const windowId = match[1];
					const regex = new RegExp(`window:${windowId}`);
					const connection = hub.connections.find(c => regex.test(c.ctx));

					if (connection) {
						return connection;
					}
				}
			}
		}

		return this.next.routeCall(hub, command, arg, cancellationToken);
	}