S3_Uploads::get_instance PHP Method

    public static function get_instance()
    {
        if (!self::$instance) {
            self::$instance = new S3_Uploads(S3_UPLOADS_BUCKET, defined('S3_UPLOADS_KEY') ? S3_UPLOADS_KEY : null, defined('S3_UPLOADS_SECRET') ? S3_UPLOADS_SECRET : null, defined('S3_UPLOADS_BUCKET_URL') ? S3_UPLOADS_BUCKET_URL : null, S3_UPLOADS_REGION);
        }
        return self::$instance;
    }

function s3_uploads_init()
{
    if (!defined('S3_UPLOADS_BUCKET') || !defined('S3_UPLOADS_KEY') || !defined('S3_UPLOADS_SECRET')) {
        return;
    }
    $instance = S3_Uploads::get_instance();
    $instance->register_stream_wrapper();
    add_filter('upload_dir', array($instance, 'filter_upload_dir'));
    add_filter('wp_image_editors', array($instance, 'filter_editors'), 9);
    remove_filter('admin_notices', 'wpthumb_errors');
    add_action('wp_handle_sideload_prefilter', array($instance, 'filter_sideload_move_temp_file_to_s3'));
}