Braintree\Http::getCaFile PHP Method

    private function getCaFile()
    {
        static $memo;
        if ($memo === null) {
            $caFile = $this->_config->caFile();
            if (substr($caFile, 0, 7) !== 'phar://') {
                return $caFile;
            }
            $extractedCaFile = sys_get_temp_dir() . '/api_braintreegateway_com.ca.crt';
            if (!file_exists($extractedCaFile) || sha1_file($extractedCaFile) != sha1_file($caFile)) {
                if (!copy($caFile, $extractedCaFile)) {
                    throw new Exception\SSLCaFileNotFound();
                }
            }
            $memo = $extractedCaFile;
        }
        return $memo;
    }