Got Empty Std::class Response

[ksspam]

I got empty std:class response for this below code

$this->soapWrapper->add('CN_Number', function ($service) {
            $service->wsdl("http://<url>?wsdl")
            ->trace(true)
            ->cache(WSDL_CACHE_NONE)
            ->options([
            'login' => $this->username,
            'password' => $this->password,
            // 'soap_version'=> SOAP_1_2,
            'exceptions'=>true,
            'stream_context' => stream_context_create(
            array(
                'ssl' => array(
                    'verify_peer'       => false,
                    'verify_peer_name'  => false,
                )
            )
        )
        ]);
        });
       $xml="XML_REQUEST";
        $query = new \SoapVar($xml, XSD_ANYXML);
        // dd($query);
       $result=$this->soapWrapper->call('CN_Number.GetCbt_ntc_validat_cn_no_ser',[$query]);
       print_r($result);
       exit;