'Mulpyplex across several stashes.
:param stashes: the stashes to mulpyplex
:return: a mulpyplexed list of states from the stashes in question, in the specified order'

def mulpyplex(self, *stashes):

    return mulpyplexer.MP(list(itertools.chain.from_iterable((self.stashes[s] for s in stashes))))
