src/vs/workbench/contrib/files/browser/views/explorerViewer.ts/ExplorerCompressionDelegate/isIncompressible
class ExplorerCompressionDelegate:	isIncompressible(stat: ExplorerItem): boolean {
		return stat.isRoot || !stat.isDirectory || stat instanceof NewExplorerItem || (!stat.parent || stat.parent.isRoot);
	}