You're playing the "what if" game. There is nothing to indicate that anything of the sort took place. Once again, I'm not opposed to the Bidens testifying if it helps clear things up. I think it's deflection and not germane to the central question at hand (Did Trump leverage military aid to the Ukraine against their President's willingness to do him a campaign favor?), but if it gets the main players (Bolton, Guiliani, Barr, Nunes, Pompeo, Mulvaney, Perry, Hyde, Parnas, Fruman) in this story to testify? Then it should happen.