static void Main(string[] args)
{
var root = new Composite("Classification of Animals");
var invertebrates = new Composite("+ Invertebrates");
var vertebrates = new Composite("+ Vertebrates");
var warmBlooded = new Leaf("-- Warm-Blooded");
var coldBlooded = new Leaf("-- Cold-Blooded");
var withJointedLegs = new Leaf("-- With Jointed-Legs");
var withoutLegs = new Leaf("-- Without Legs");
invertebrates.Add(withJointedLegs);
invertebrates.Add(withoutLegs);
vertebrates.Add(warmBlooded);
vertebrates.Add(coldBlooded);
root.Add(invertebrates);
root.Add(vertebrates);
root.PrintName();
}