public virtual void TestReplace()
{
var c = new Collection4();
c.Replace("one", "two");
c.Add("one");
c.Add("two");
c.Add("three");
c.Replace("two", "two.half");
AssertCollection(new[] {"one", "two.half", "three"}, c);
c.Replace("two.half", "one");
c.Replace("one", "half");
AssertCollection(new[] {"half", "one", "three"}, c);
}