src/vs/platform/windows/electron-main/windowsStateHandler.ts/serializeWindowState
function serializeWindowState(windowState: IWindowState): ISerializedWindowState {
	return {
		workspaceIdentifier: windowState.workspace && { id: windowState.workspace.id, configURIPath: windowState.workspace.configPath.toString() },
		folder: windowState.folderUri && windowState.folderUri.toString(),
		backupPath: windowState.backupPath,
		remoteAuthority: windowState.remoteAuthority,
		uiState: windowState.uiState
	};
}