private function profileEndpointUrl()
 {
     $profileEnvt = strtolower($this->config->isSandbox()) ? "api.sandbox" : "api";
     if (!empty($this->config->getRegion())) {
         $region = strtolower($this->config->getRegion());
         if (array_key_exists($region, $this->regionMappings)) {
             $this->profileEndpoint = 'https://' . $profileEnvt . '.' . $this->profileEndpointUrls[$region];
         } else {
             throw new \Exception($region . ' is not a valid region');
         }
     } else {
         throw new \Exception("config['region'] is a required parameter and is not set");
     }
 }