As a "noob" (nothing wrong with that; we all were, once and some still are after years of experience), you're not giving us much to go on.

Specifically, you're giving us no way to check your code for typos that make it vary from the wiki entry (assuming that the wiki version is correct, which it ain't, always).

So, here's a boilerplate idea: post a minimal but executable snippet of your code that illustrates your attempt to "get the upstream sequence" (your post seems to indicate that's where the problem is; if that's incorrect, correct me); the error message(s), if any, or narrative explanation of what "isn't working for me" means, exactly; and a small amount of sample data.