FluidXml\FluidContext::offsetSet PHP 메소드

    public function offsetSet($offset, $value)
    {
        // if (\is_null($offset)) {
        //         $this->nodes[] = $value;
        // } else {
        //         $this->nodes[$offset] = $value;
        // }
        throw new \Exception('Setting a context element is not allowed.');
    }