src/vs/workbench/contrib/codeEditor/browser/outline/documentSymbolsTree.ts/DocumentSymbolGroupRenderer/renderTemplate
class DocumentSymbolGroupRenderer:	renderTemplate(container: HTMLElement): DocumentSymbolGroupTemplate {
		const labelContainer = dom.$('.outline-element-label');
		container.classList.add('outline-element');
		dom.append(container, labelContainer);
		return new DocumentSymbolGroupTemplate(labelContainer, new HighlightedLabel(labelContainer));
	}