public void TestRemoveAndAdd_RemovedAndAdded()
{
_set.CollectionChanged += (sender, args) =>
{
CollectionAssert.AreEquivalent(new[] { "item 3" }, args.RemovedItems);
CollectionAssert.AreEquivalent(new[] { "item 4" }, args.AddedItems);
};
_set.RemoveAndAdd("item 3", "item 4");
CollectionAssert.AreEquivalent(new[] { "item 1", "item 2", "item 4" }, _set);
ExpectChangeCalls(1, 0);
}