// Set up valid root CA certificate.
$options = [];
if (true === is_file(__DIR__.DIRECTORY_SEPARATOR.'cacert.pem')) {
$options[CURLOPT_SSL_VERIFYPEER] = true;
$options[CURLOPT_SSL_VERIFYHOST] = 2;
$options[CURLOPT_CAINFO] = __DIR__.DIRECTORY_SEPARATOR.'cacert.pem';
}
// Init target.
$this->billPayments = new BillPayments($this->config['merchantSecretKey'], $options);