none said:
Silverwook wrote: "As he's seen doing this in the Marvel comic, could it have been in the script at some point?"
http://www.starwarz.com/tbone/vaders-floating-cup/
Quote: "As it turns out, this scene with the cup is in both the Janusary 1, 1976 and March 15, 1976 versions of the script. In the January version there is even a second bit in which Vader uses the force to crush the cup. This part is not included in the March 15 revision."
this was when vader didn't where a mask as per zombies book.