'L{CommandDispatcher} should relay its unhandled errors in responding to
boxes to its boxSender.'

def test_sendUnhandledError(self):

    err = RuntimeError('something    went    wrong,    oh    no')
    self.sender.expectError()
    self.dispatcher.unhandledError(Failure(err))
    self.assertEqual(len(self.sender.unhandledErrors), 1)
    self.assertEqual(self.sender.unhandledErrors[0].value, err)
