Filter TreeNodeCollection based on backend user permissions

Questions
1

I have created a custom section that I would like display only the nodes that are available to the backend user who is currently logged in.
(Basically, what I want is the nodes shown to a given backend user in the content section.)

I have implemented GetTreeNodes of my TreeController like this:

 protected override TreeNodeCollection GetTreeNodes(string id, FormDataCollection queryStrings)
    {
        var nodes = new TreeNodeCollection();
        
        var rootNodeId = Constants.System.Root.ToInvariantString();
        //check if we’re rendering the root node’s children
        if (id == rootNodeId)
        {
            foreach (var node in Umbraco.ContentAtRoot().ToList())
            {
                var permissions = helper.GetCurrentUmbracoUser().GetPermissions(node.Path);
                if (permissions == "-") continue;

                var treeNode = CreateTreeNode(node.Id.ToString(), rootNodeId, queryStrings, node.Name, "icon-home", false);
                nodes.Add(treeNode);
            }
        }
        return nodes;
    }

The method works as expected but I was hoping for more robust way to do this.

Pre-v7 code samples show code similar to this:

Umbraco.ContentAtRoot().Where("HasAccess").ToList()

However, they do not appear to work in current versions.

Does someone know of a better way to do the above in V7?

This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/69628-filter-treenodecollection-based-on-backend-user-permissions