//test case
static void Main(string[] args)
{
var c = new Node <char>('C');
var e = new Node <char>('E');
var h = new Node <char>('H');
var a = new Node <char>('A');
var d = new Node <char>('D', c, e);
var i = new Node <char>('I', h);
var b = new Node <char>('B', a, d);
var g = new Node <char>('G', right: i);
var f = new Node <char>('F', b, g);
Console.Write("Level order traversal sequence: ");
foreach (var x in TreeTraversal.AsBreadthFirst(f))
{
Console.Write(x + " ");
}
Console.WriteLine();
}