Auth0\SDK\API\Helpers\RequestBuilder::getParams PHP Method

    public function getParams()
    {
        if (empty($this->params)) {
            return '';
        }
        $params = array_map(function ($key, $value) {
            return "{$key}={$value}";
        }, array_keys($this->params), $this->params);
        return '?' . implode('&', $params);
    }

 public function testParams()
 {
     $builder = new RequestBuilder(['domain' => 'www.domain.com', 'method' => 'get']);
     $builder->withParam('param1', 'value1');
     $this->assertEquals('?param1=value1', $builder->getParams());
     $builder->withParam('param2', 'value2');
     $this->assertEquals('?param1=value1&param2=value2', $builder->getParams());
     $builder->withParams([['key' => 'param3', 'value' => 'value3'], ['key' => 'param1', 'value' => 'value4']]);
     $this->assertEquals('?param1=value4&param2=value2&param3=value3', $builder->getParams());
 }