src/vs/workbench/api/browser/mainThreadTreeViews.ts/TreeViewDataProvider/updateTreeItem
class TreeViewDataProvider:	private updateTreeItem(current: ITreeItem, treeItem: ITreeItem): void {
		treeItem.children = treeItem.children ? treeItem.children : undefined;
		if (current) {
			const properties = distinct([...Object.keys(current instanceof ResolvableTreeItem ? current.asTreeItem() : current),
			...Object.keys(treeItem)]);
			for (const property of properties) {
				(<any>current)[property] = (<any>treeItem)[property];
			}
			if (current instanceof ResolvableTreeItem) {
				current.resetResolve();
			}
		}
	}