If it is what I think it is... (Brake booster) then you ask the testing inspector to stand IN FRONT of his work,, If he refuses, it's bad. Though I worded it as a joke, It really is serious.
On many motor homes the brakes use a Hydro booster system instead of a vacuum booster like on a car, this runs off the power steering pump or an electric pump if the engine is off.
If you stand on the brakes and it keeps on rolling, said booster (or something else) is bad. Thus if the inspector is Standing in front of his work" he gets splatted.
Home is where I park it!