public async Task Should_Not_Substitue_Existing_Operation_Id_If_Context_Contains_Null()
{
OperationIdContext.Set("test");
var context = new MockOwinContext();
var collector = new OperationIdCollectingMiddleware();
var sut = new RestoreOperationIdContextMiddleware(collector);
await sut.Invoke(context);
collector.OperationIdFromAmbientContext.Should().Be("test");
}