protected function _makeCall($function, $params = null, $method = 'GET') {
        if (isset($params['count']) && $params['count'] < 1) {
            throw new InvalidParameterException('InstagramClient: you are trying to query 0 records!');
        }

        // if the call needs an authenticated user
        if (true === isset($this->_accesstoken)) {
            $authMethod = '?access_token=' . $this->getAccessToken();
        } else {
            throw new AuthException("Error: _makeCall() | This method requires an valid users access token.");
        }

        if (isset($params) && is_array($params)) {
            $paramString = '&' . http_build_query($params);
        } else {
            $paramString = null;
        }

        $apiCall = self::API_URL . $function . $authMethod . (('GET' === $method) ? $paramString : null);

        // we want JSON
        $headerData = array('Accept: application/json');

        if ($this->_enforceSignedRequests) {
            $apiCall .= (strstr($apiCall, '?') ? '&' : '?') . 'sig=' . $this->_signHeader($function, $authMethod, $params);
        }

        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $apiCall);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headerData);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

        if ('POST' === $method) {
            curl_setopt($ch, CURLOPT_POST, count($params));
            curl_setopt($ch, CURLOPT_POSTFIELDS, ltrim($paramString, '&'));
        } else if ('DELETE' === $method) {
            curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'DELETE');
        }

        $jsonData = curl_exec($ch);

        $httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

        if(403 === $httpcode) {
            $error = json_decode($jsonData, true);
            throw new CurlException('_makeCall() - ' . $error['error_type'] . ' error: ' . $error['error_message']);
        }

        if (false === $jsonData) {
            throw new CurlException('_makeCall() - cURL error: ' . curl_error($ch));
        }
        curl_close($ch);

        return json_decode($jsonData);
    }