def add(self, elem, replace=False):
        """Add a requirement.

        :param elem: a string or :class:`Requirement` instance.
        :param replace: if `True`, packages in the set with the same name will
            be removed first.
        """
        if isinstance(elem, text_type):
            elem = Requirement.coerce(elem)
        if replace and elem in self:
            self.remove(elem)
        super(Requirements, self).add(elem)
def _load_from_data(self, data):
        self._replay_data = data
        self._verify_toplevel_json(self._replay_data)

        self._rpms = self._replay_data.get("rpms", [])
        self._assert_type(self._rpms, list, "rpms", "array")

        self._groups = self._replay_data.get("groups", [])
        self._assert_type(self._groups, list, "groups", "array")

        self._environments = self._replay_data.get("environments", [])
        self._assert_type(self._environments, list, "environments", "array")