src/vs/workbench/contrib/tags/electron-sandbox/workspaceTagsService.ts/WorkspaceTagsService/parentURI
class WorkspaceTagsService:	private parentURI(uri: URI | undefined): URI | undefined {
		if (!uri) {
			return undefined;
		}
		const path = uri.path;
		const i = path.lastIndexOf('/');
		return i !== -1 ? uri.with({ path: path.substr(0, i) }) : undefined;
	}