code: protected function makeCall($service, $params, $fieldKey, $fieldValue)
      {
          // the response object has a lot of value-add data, that may help to enhance lead data, for a future feature request
  
          // @todo - Update to use Guzzle.
  
          // set a timeout default to 20 seconds
          $settings = ['curl_options' => [CURLOPT_CONNECTTIMEOUT => 2, CURLOPT_TIMEOUT => 3]];
  
          $url      = "http://www.xverify.com/services/$service/verify/?$fieldKey=$fieldValue"; // valid entries for service: "emails", "phone", "address"
          $response = $this->makeRequest(
              $url,
              ['append_to_query' => $params],
              'GET',
              $settings
          );
  
          return $response;
      }
docs: @param $service
  @param $params
  @param $fieldKey
  @param $fieldValue
  
  @return mixed|string