How to Invert a Conditional Clause

If you had needed advice, we can invert it and say, I would have been there to give it to you. This is one of the rare times you'll see inversions, and it's not a question. So this is talking about something in the past that's unchangeable. Another example could be had I been you, I'd have been nicer. And these are the same with these clauses. The same thing here with the inversion, okay?