src/vs/platform/update/common/updateIpc.ts/UpdateChannel/call
class UpdateChannel:	call(_: unknown, command: string, arg?: any): Promise<any> {
		switch (command) {
			case 'checkForUpdates': return this.service.checkForUpdates(arg);
			case 'downloadUpdate': return this.service.downloadUpdate();
			case 'applyUpdate': return this.service.applyUpdate();
			case 'quitAndInstall': return this.service.quitAndInstall();
			case '_getInitialState': return Promise.resolve(this.service.state);
			case 'isLatestVersion': return this.service.isLatestVersion();
		}

		throw new Error(`Call not found: ${command}`);
	}