'Wait operation fires after specified time.'

def test_wait(self):

    seconds = 10
    clock = Clock()
    op = Wait(clock, None, wait_seconds=seconds)
    probe = op.get_probe()
    d = probe.run()
    d.addCallback((lambda ignored: probe.cleanup))
    self.assertNoResult(d)
    clock.advance(seconds)
    self.successResultOf(d)
