public function _post($endpoint = '', array $params = [], $cookieStorage = false) {
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $endpoint);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($params));
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
    if ($cookieStorage != FALSE) {
        curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.101 Safari/537.36');
        curl_setopt($ch, CURLOPT_COOKIEJAR, $cookieStorage);
        curl_setopt($ch, CURLOPT_COOKIEFILE, $cookieStorage);
    }
    $response = curl_exec($ch);
    curl_close($ch);
    return $response;
}

public function login($username = '', $password = '') {
    $result = $this->_post(self::$BASE_URL . '/ucp.php?mode=login', [
        'username' => $username,
        'password' => $password,
        'redirect' => '/viewforum.php',
        'login' => 'Login',
        'sid' => ''
            ], $this->cookieFile);
    if (preg_match('/' . $username . '/i', $result)) {
        return TRUE;
    } elseif (preg_match('/whoops/i', $result)) {
        return $result;
    } else {
        return FALSE;
    }
}