def test_mul_many_numbers():
s = range(1, 10)
assert Calc.mul(*s) == 362880
def test_mul_by_zero_raises_exception():
c = Calc()
with pytest.raises(ValueError):
c.mul(3, 0)
def test_mul_two_numbers():
c = Calc()
res = c.mul(6, 4)
assert res == 24