Electrical Receptacles

I had few electrical receptacles, and none conveniently located. And I wanted to avoid stringing extension cords all over the garage. With a compressor and other heavy duty tools I wanted new receptacles on a 20 amp circuit. Fortunately after some sleuthing (the previous home owner had hidden it) I was able to find a single unused 20 amp wall socket that was originally for a central vacuum system that was never installed. I had an electrician tap off that and run multiple sockets along the wall. I considered doing it myself but was unclear about code issues so turned it over to a pro.