def groups_option(f):
    new_func = click.option("-g", "--groups",
                            help="Comma-separated list of requirement groups "
                            "to include.")(f)
    return update_wrapper(new_func, f)
def _raise_or_warn(self, warn_only, msg):
        if warn_only:
            self._warnings.append(msg)
        else:
            raise TransactionError(msg)