def save(self, filename=None):
        filename = Path(filename) if filename is not None else self.filename
        with filename.open("w") as f:
            f.write(self.yaml)
def test_ccode_exceptions():
    assert ccode(ceiling(x)) == "ceil(x)"
    assert ccode(Abs(x)) == "fabs(x)"
    assert ccode(gamma(x)) == "tgamma(x)"