void TreeNodeCreated(object sender, TreeViewEventArgs e)
        {
            SolutionNode sn = e.Node as SolutionNode;

            if (sn != null)
            {
                GitStatusCache.ClearCachedStatus(sn.Solution.FileName);
                OverlayIconManager.Enqueue(sn);
            }
            else
            {
                DirectoryNode dn = e.Node as DirectoryNode;
                if (dn != null)
                {
                    OverlayIconManager.Enqueue(dn);
                }
                else
                {
                    FileNode fn = e.Node as FileNode;
                    if (fn != null)
                    {
                        OverlayIconManager.Enqueue(fn);
                    }
                }
            }
        }