def __init__(self, package, version):
        """Construct a new requirement.

        :param package: the package name.
        :param version: a semver compatible version specification.
        """
        self.package = package
        self.version = version
        if self.version and not re.match(r"[<=>~]", version[:2]):
            self.version = "=={}".format(self.version)
def _prepare_filename(
        self, action_name: Optional[str] = None, extension: str = ".txt", split_token: str = "-"
    ) -> str:
        args = []
        if self._stage is not None:
            args.append(self._stage)
        if self.filename:
            args.append(self.filename)
        if self._local_rank is not None:
            args.append(str(self._local_rank))
        if action_name is not None:
            args.append(action_name)
        filename = split_token.join(args) + extension
        return filename