public function method($method)
    {
        $method  = strtolower($method);
        $builder = new RequestBuilder([
            'domain' => $this->domain,
            'basePath' => $this->basePath,
            'method' => $method,
            'guzzleOptions' => $this->guzzleOptions,
            'returnType' => $this->returnType,
        ]);
        $builder->withHeaders($this->headers);

        if (in_array($method, [ 'patch', 'post', 'put' ])) {
            $builder->withHeader(new ContentType('application/json'));
        }

        return $builder;
    }