static void Main(string[] args)
{
Tree <string> t = new Tree <string>("node 0");
//Adding children in layer 1
t.AddChild("node A");
t.AddChild("node B");
t.AddChild("node C");
t.AddChild("node D");
t.AddChild("node E");
//Adding children in layer 2 via index
t.children[0].AddChild("node 1");
t.children[0].AddChild("node 2");
t.children[1].AddChild("node 3");
t.children[1].AddChild("node 4");
t.children[1].AddChild("node 5");
//Adding children via variable
Tree <string> D = t.children[3];
D.AddChild("node 6");
D.AddChild("node 7");
//Printing tree
t.PrintTree();
Console.ReadLine();
}