private static TreeElement BuildTree(this TreeElement root, List <TreeElement> elements)
{
if (elements.Count == 0)
{
return(root);
}
var children = root.FetchChildren(elements).ToList();
root.Children.AddRange(children);
root.RemoveChildren(elements);
for (int i = 0; i < children.Count; i++)
{
children[i] = children[i].BuildTree(elements);
if (elements.Count == 0)
{
break;
}
}
return(root);
}