public function offsetSet($name, $value)
    {
        if (is_int($name)) {
            parent::offsetSet($name, $value);
            // @codeCoverageIgnoreStart
            // This will never be reached, because an exception is always
            // thrown.
            return;
            // @codeCoverageIgnoreEnd
        }

        $param = new Parameter($this->root, $name, $value);
        $this->parameters[$param->name] = $param;
    }