public void TestTryGetElement()
 {
     var wrapper = new BsonDocumentWrapper(new BsonDocument("x", 1));
     Assert.AreEqual(false, wrapper.IsMaterialized);
     BsonElement element;
     var result = wrapper.TryGetElement("x", out element);
     Assert.AreEqual(true, wrapper.IsMaterialized);
     Assert.AreEqual(true, result);
     Assert.AreEqual("x", element.Name);
     Assert.AreEqual(new BsonInt32(1), element.Value);
 }