'verify that invalid parameters are forbidden'

def test_rounding_invalid(self):

    with self.assertRaises(AssertionError):
        float_is_zero(0.01, precision_digits=3, precision_rounding=0.01)
    with self.assertRaises(AssertionError):
        float_compare(0.01, 0.02, precision_digits=3, precision_rounding=0.01)
    with self.assertRaises(AssertionError):
        float_round(0.01, precision_digits=3, precision_rounding=0.01)
