public void MoveNodeToUnderParent(ITreeItem newParent, ITreeItem nodeToMove)
{
if (newParent == null)
{
throw new ArgumentNullException(nameof(newParent));
}
if (newParent.IsDescendantOf(nodeToMove))
{
return;
}
nodeToMove.Parent.RemoveChild(nodeToMove);
newParent.AddChild(nodeToMove);
}