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 do_register_cli_opts(opt, ignore_errors=False):
    # TODO: This function has broken name, it should work with lists :/
    if not isinstance(opt, (list, tuple)):
        opts = [opt]
    else:
        opts = opt

    try:
        cfg.CONF.register_cli_opts(opts)
    except:
        if not ignore_errors:
            raise