In the version of twisted we're using we can't actually use `assertNoResult` because of https://twistedmatrix.com/trac/ticket/6291

We'd have to upgrade to 13.1.  To assert that d1 and d2 have no result and then also check that they have the correct result.  The easiest thing to do is to change the expected result to make sure it's not squashed by other mocking.