public void TestMergeOverwrite()
{
var wrapper = new BsonDocumentWrapper(new BsonDocument("x", 1));
Assert.AreEqual(false, wrapper.IsMaterialized);
var result = wrapper.Merge(new BsonDocument("x", 2), true);
Assert.AreEqual(true, wrapper.IsMaterialized);
Assert.AreSame(wrapper, result);
Assert.AreEqual(1, wrapper.ElementCount);
Assert.AreEqual("x", wrapper.GetElement(0).Name);
Assert.AreEqual(new BsonInt32(2), wrapper[0]);
}
