public static void RemoveAllFileNodesExcept(DirNode rootNode, HashSet <FileNode> except)
{
List <FileNode> nodesToRemove = new List <FileNode>();
foreach (FileNode fileNode in rootNode.EnumerateFileNodesRecursively())
{
if (!except.Contains(fileNode))
{
nodesToRemove.Add(fileNode);
}
}
foreach (FileNode nodeToRemove in nodesToRemove)
{
nodeToRemove.Parent.DeleteFileNode(nodeToRemove.Name);
}
}