src/vs/platform/extensions/electron-main/extensionHostStarter.ts/ExtensionHostStarter/_getExtHost
class ExtensionHostStarter:	private _getExtHost(id: string): ExtensionHostProcess | UtilityExtensionHostProcess {
		const extHostProcess = this._extHosts.get(id);
		if (!extHostProcess) {
			throw new Error(`Unknown extension host!`);
		}
		return extHostProcess;
	}