anchor.diff:              try
                   let folders = Directory.EnumerateDirectories wp |> Seq.map this.FolderNode
                   let files = Directory.EnumerateFiles wp |> Seq.map FileInfo |> Seq.map this.FileNode
  -                Seq.append folders files |> Seq.toList
  +                let nodes = Seq.append folders files |> Seq.toList
  +                if nodes.IsEmpty then
  +                    this.ErrorNode (Exception("Empty Folder")) (this.Parent path) |> List.singleton
  +                else nodes
               with | ex -> this.ErrorNode ex (this.Parent path) |> List.singleton
   
       member this.FileNode file = {
  
positive.code:         let error = ex.Message.Split('\r', '\n').[0]
          {
              Path = path
              Name = sprintf "<Error: %s>" error
              Type = NodeType.Error
              Modified = None
              Size = None
  
negative.code: ﻿namespace Koffee
  
  open System
  open System.IO
  open Koffee
  
  