src/vs/platform/windows/electron-main/windowsStateHandler.ts/WindowsStateHandler/toWindowState
class WindowsStateHandler:	private toWindowState(window: ICodeWindow): IWindowState {
		return {
			windowId: window.id,
			workspace: isWorkspaceIdentifier(window.openedWorkspace) ? window.openedWorkspace : undefined,
			folderUri: isSingleFolderWorkspaceIdentifier(window.openedWorkspace) ? window.openedWorkspace.uri : undefined,
			backupPath: window.backupPath,
			remoteAuthority: window.remoteAuthority,
			uiState: window.serializeWindowState()
		};
	}