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 anypats(self):
        """None of .always(), .isexact(), and .prefix() is true --
        optimizations will be difficult."""
        return not self.always() and not self.isexact() and not self.prefix()