InterNations\Component\HttpMock\Matcher\ExtractorFactory::createParamExtractor PHP Method

    public function createParamExtractor($param)
    {
        return static function (Request $request) use($param) {
            return $request->query->get($param);
        };
    }

 public function queryParamIs($param, $matcher)
 {
     $this->appendMatcher($matcher, $this->extractorFactory->createParamExtractor($param));
     return $this;
 }