public function has(string $key): bool
    {
        return isset(array_flip(array_column($this->pairs, 0))[$key]);
    }
public function has(string $key): bool
    {
        return isset(array_flip(array_column($this->pairs, 0))[$key]);
    }
public function has ( string $ key ) : bool { return isset ( array_flip ( array_column ( $ this -> pairs , 0 ) ) [ $ key ] ) ; }
Tell whether a parameter with a specific name exists.

@see https://url.spec.whatwg.org/#dom-urlsearchparams-has
Tell whether a parameter with a specific name exists .