collapseAllRows() causes a crash when called in didSelectRowAt

[swiatrzyk]

I'm about to implement that when there is a child that is not expandable, then return selected cell + collapse whole treeView.
But when I call collapseAllRows() in didSelectRowAt, there goes a crash.
You can replicate that in demo project by adding:

    func treeView(_ treeView: CITreeView, didSelectRowAt treeViewNode: CITreeViewNode, at indexPath: IndexPath) {
        guard let cellData = treeViewNode.item as? CITreeViewData else {fatalError()}
        if cellData.children.isEmpty {
            self.sampleTreeView.collapseAllRows()
        }
    }

Pod version: 1.6.1
Then tap Sedan -> Alfa Romeo.
After that there goes "Index out or range error" in setExpandTreeViewNode of CTTreeViewController.