How can I dynamic change object options about AWS?

$object = AWS::createClient('s3');

I create a object about s3, and the region is us-east-1. I want to dynamic change the region to ap-southeast-1 or others. So, How can I do that? I use get_class_methods method to print $object all functions, and I find factory method, But it does not work.

$object->factory([
    'region' => 'ap-southeast-1',
    'scheme' => 'http',
    'version' => 'latest'
]);