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 visitdir(self, dir):
        r = False
        for m in self._matchers:
            v = m.visitdir(dir)
            if v == "all":
                return v
            r |= v
        return r