private function transfer(RequestInterface $request, array $options)
{
// save_to -> sink
if (isset($options['save_to'])) {
$options['sink'] = $options['save_to'];
unset($options['save_to']);
}
// exceptions -> http_errors
if (isset($options['exceptions'])) {
$options['http_errors'] = $options['exceptions'];
unset($options['exceptions']);
}
$request = $this->applyOptions($request, $options);
$handler = $options['handler'];
try {
return Promise\promise_for($handler($request, $options));
} catch (\Exception $e) {
return Promise\rejection_for($e);
}
}