Vacuum breaker on hand held shower with dual check valve?

We're installing a new hand held shower (Hansgrohe). The wall outlet includes dual check valves. Is there any reason we also need to (or would want to) put on a vacuum breaker? I already have it, I'm just not sure if it makes sense to use it.

Thanks,

Ken

It will be easier to convince the inspector it is to code with it installed. You really don't want it sitting in the tub and a hiccup draw water into the supply and pollute it, so a secondary control isn't a bad idea. I'm not sure about the codes WRT this.

It's a stall shower, and I don't think the hose is long enough for the head to reach the pan. But since I have it anyway, I suppose it wouldn't hurt to put it on (I was going to return it if I didn't need it, but hey, what's another $35? ). Thanks!