src/vs/workbench/contrib/files/browser/fileActions.ts/openFilePreserveFocusHandler
export const openFilePreserveFocusHandler = async (accessor: ServicesAccessor) => {
	const editorService = accessor.get(IEditorService);
	const explorerService = accessor.get(IExplorerService);
	const stats = explorerService.getContext(true);

	await editorService.openEditors(stats.filter(s => !s.isDirectory).map(s => ({
		resource: s.resource,
		options: { preserveFocus: true }
	})));
};