src/vs/workbench/contrib/files/browser/views/explorerView.ts/ExplorerView/updateAnyCollapsedContext
class ExplorerView:	private updateAnyCollapsedContext(): void {
		const treeInput = this.tree.getInput();
		if (treeInput === undefined) {
			return;
		}
		const treeInputArray = Array.isArray(treeInput) ? treeInput : Array.from(treeInput.children.values());
		// Has collapsible root when anything is expanded
		this.viewHasSomeCollapsibleRootItem.set(hasExpandedNode(this.tree, treeInputArray));
	}