'L{htb.Bucket.drip} returns C{True} if the bucket is empty after that drip.'

def test_bucketEmpty(self):

    b = SomeBucket()
    b.add(20)
    self.clock.set(9)
    empty = b.drip()
    self.assertFalse(empty)
    self.clock.set(10)
    empty = b.drip()
    self.assertTrue(empty)
