public void TestDeepClone()
{
var wrapper = new BsonDocumentWrapper(new BsonDocument("x", 1));
Assert.AreEqual(false, wrapper.IsMaterialized);
var deepClone = wrapper.DeepClone();
Assert.AreEqual(true, wrapper.IsMaterialized);
Assert.IsInstanceOf<BsonDocument>(deepClone);
Assert.AreEqual(wrapper, deepClone);
}