src/vs/base/browser/ui/tree/abstractTree.ts/TreeRenderer/onDidChangeNodeTwistieState
class TreeRenderer:	private onDidChangeNodeTwistieState(node: ITreeNode<T, TFilterData>): void {
		const data = this.renderedNodes.get(node);

		if (!data) {
			return;
		}

		this.renderTwistie(node, data.templateData);
		this._onDidChangeActiveNodes(this.activeNodes.elements);
		this.renderIndentGuides(node, data.templateData);
	}