def test_factors(self):
primes = Primes()
assert primes.factors(0) == []
assert primes.factors(1) == []
assert primes.factors(2) == [2]
assert primes.factors(6) == [2, 3]
assert primes.factors(8) == [2, 2, 2]
assert primes.factors(29) == [29]
