code: public function request($endPoint, $httpVerb = 'GET', $data = array())
      {
          // Validate API
          if (!$this->apiKey) {
              throw new \Exception('MailChimp API Key must be set before making request!');
          }
          
          $endPoint = ltrim($endPoint, '/');
          $httpVerb = strtoupper($httpVerb);
          $requestUrl = $this->apiUrl.$endPoint;
          
          return $this->curlRequest($requestUrl, $httpVerb, $data);
      }
docs: Call MailChimp API
  @param string $endPoint - (http://kb.mailchimp.com/api/resources)
  @param string $httpVerb
  @param array $data - Optional
  @return array