src/vs/workbench/contrib/markers/browser/markersTreeViewer.ts/ResourceMarkersRenderer/onDidChangeRenderNodeCount
class ResourceMarkersRenderer:	private onDidChangeRenderNodeCount(node: ITreeNode<ResourceMarkers, ResourceMarkersFilterData>): void {
		const templateData = this.renderedNodes.get(node);

		if (!templateData) {
			return;
		}

		this.updateCount(node, templateData);
	}