public function addOr(Expr $subexpression /*, $subexpression2, ... */)
    {
        $or = new Condition\Logical\AddOr;
        $or->add(...array_map(
            function (Expr $expr) {
                return $expr->condition;
            },
            func_get_args()
        ));

        $this->addCondition($or);

        return $this;
    }