public static function where($key, $operatorOrValue=null, $value=null)
    {
        $g = new ConditionGroup();

        if (func_num_args() == 1) {
            return $g->where($key);
        }

        if (func_num_args() == 2) {
            return $g->where($key, $operatorOrValue);
        }

        return $g->where($key, $operatorOrValue, $value);

    }