public function haveSoapHeader($header, $params = [])
    {
        $soap_schema_url = $this->config['schema_url'];
        $xml = $this->xmlRequest;
        $xmlHeader = $xml->documentElement->getElementsByTagNameNS($soap_schema_url, 'Header')->item(0);
        $headerEl = $xml->createElement($header);
        SoapUtils::arrayToXml($xml, $headerEl, $params);
        $xmlHeader->appendChild($headerEl);
    }