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 deserialize(self, value):
        value = decode(value)
        if "\n" in value:
            values = re.split(r"\s*\n\s*", value)
        else:
            values = re.split(r"\s*,\s*", value)
        values = tuple(v.strip() for v in values if v.strip())
        validators.validate_required(values, self._required)
        return tuple(values)