func (o *Ordered) PutDir(path string) {
	path = clean(path)
	if path == "" {
		return
	}
	nodeProto := &NodeProto{
		Name:    base(path),
		DirNode: &DirectoryNodeProto{},
	}
	o.putDir(path, nodeProto)
}
func (o *Ordered) PutDir(path string) {
	path = clean(path)
	if path == "" {
		return
	}
	nodeProto := &NodeProto{
		Name:    base(path),
		DirNode: &DirectoryNodeProto{},
	}
	o.putDir(path, nodeProto)
}
// PutDir puts a directory in the hashtree.