src/vs/platform/workspace/common/virtualWorkspace.ts/getVirtualWorkspaceLocation
export function getVirtualWorkspaceLocation(workspace: IWorkspace): { scheme: string; authority: string } | undefined {
	if (workspace.folders.length) {
		return workspace.folders.every(f => isVirtualResource(f.uri)) ? workspace.folders[0].uri : undefined;
	} else if (workspace.configuration && isVirtualResource(workspace.configuration)) {
		return workspace.configuration;
	}
	return undefined;
}