def test_is_present(self):
premise = Premise(1)
premise.probability = 1
for i in range(100):
self.assertTrue(premise.is_present())
premise.probability = 0.5
sum = 0.0
for i in range(100000):
if premise.is_present():
sum += 1
sum /= 100000.0
self.assertAlmostEquals(sum, 0.5, 2)
