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 __init__(self, choices=None, optional=False):
        super().__init__(
            minimum=0, maximum=2 ** 16 - 1, choices=choices, optional=optional
        )