public void Duplicate()
{
TreeModel <string> tm = new TreeModel <string>("",
new List <TreeModel <string> >()
{
new TreeModel <string>("section 1",
new List <TreeModel <string> >()
{
new TreeModel <string>("sec1item1"),
new TreeModel <string>("sec1item2")
}),
new TreeModel <string>("section 2"),
});
TreeModel <string> dupe = tm.Duplicate();
List <TreeModel <string> > flatTm = tm.Flatten();
List <TreeModel <string> > flatDupe = dupe.Flatten();
Assert.IsFalse(flatTm.Any(t_Tm =>
flatDupe.Any(t_Dupe => Object.ReferenceEquals(t_Tm, t_Dupe))));
Assert.IsTrue(tm.Equals(dupe));
}