You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: dom.go
    path of file: ./repos/scan4all/vendor/github.com/chromedp/cdproto/dom
    
    the code of the file until where you have to start completion: // Package dom provides the Chrome DevTools Protocol
// commands, types, and events for the DOM domain.
//
// This domain exposes DOM read/write operations. Each DOM Node is
// represented with its mirror object that has an id. Thi
    
func (p *CollectClassNamesFromSubtreeParams) Do(ctx context.Context) (classNames []string, err error) {
	// execute
	var res CollectClassNamesFromSubtreeReturns
	err = cdp.Execute(ctx, CommandCollectClassNamesFromSubtree, p, &res)
	if err != nil {
		return nil, err
	}

	return res.ClassNames, nil
}