public void ObserveElement()
{
var one = new TestModel { StringProperty = "1" };
var two = new TestModel { StringProperty = "2" };
var list = new RxList<TestModel>(one, two);
string s = null;
list.ObserveElementProperty(x => x.StringProperty).Subscribe(x => s = x.Value);
list[0].StringProperty = "foo";
Assert.AreEqual("foo", s);
list.Remove(one);
one.StringProperty = "bar";
Assert.AreEqual("foo", s);
list[0] = new TestModel { StringProperty = "3" };
Assert.AreEqual("3", s);
}