Bluz\Router\Router::setParam PHP Method

    public function setParam($key, $value)
    {
        $key = (string) $key;
        if (null === $value && isset($this->params[$key])) {
            unset($this->params[$key]);
        } elseif (null !== $value) {
            $this->params[$key] = $value;
        }
    }