'L{task.LoopingCall.withCount} with interval set to 0
will call the countCallable 1.'

def test_withCountIntervalZero(self):

    clock = task.Clock()
    accumulator = []
    def foo(cnt):
        accumulator.append(cnt)
        if (len(accumulator) > 4):
            loop.stop()
    loop = task.LoopingCall.withCount(foo)
    loop.clock = clock
    deferred = loop.start(0, now=False)
    clock.advance(0)
    self.successResultOf(deferred)
    self.assertEqual([1, 1, 1, 1, 1], accumulator)
