src/vs/workbench/contrib/markers/browser/markersTreeViewer.ts/MarkerWidget/constructor
class MarkerWidget:	constructor(
		private parent: HTMLElement,
		private readonly markersViewModel: MarkersViewModel,
		private readonly _openerService: IOpenerService,
		_instantiationService: IInstantiationService
	) {
		super();
		this.actionBar = this._register(new ActionBar(dom.append(parent, dom.$('.actions')), {
			actionViewItemProvider: (action: IAction) => action.id === QuickFixAction.ID ? _instantiationService.createInstance(QuickFixActionViewItem, <QuickFixAction>action) : undefined
		}));
		this.icon = dom.append(parent, dom.$(''));
		this.messageAndDetailsContainer = dom.append(parent, dom.$('.marker-message-details-container'));
	}