/// <summary>
/// Returns an enumerable collection of <see cref="TreeNode"/> objects containing the nodes
/// of the tree sorted in postfix order.
/// </summary>
/// <param name="node"><see cref="TreeNode"/> to start at.</param>
/// <returns>An enumerable collection of <see cref="TreeNode"/> objects containing the nodes
/// of the tree sorted in prefix order.</returns>
private static IEnumerable <TreeNode> GetPostfixTree(TreeNode?node)
{
if (node != null)
{
foreach (TreeNode childNode in node.ChildNodes)
{
foreach (TreeNode subChildNode in TreeEntityExtensions.GetPostfixTree(childNode))
{
yield return(subChildNode);
}
}
yield return(node);
}
}