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: stack.go
    path of file: ./repos/go-app/pkg/ui
    
    the code of the file until where you have to start completion: package ui

import "github.com/maxence-charriere/go-app/v9/pkg/app"

// IStack is the interface that describes a container that displays its items
// as stacked panels.
type IStack interface {
	app.UI

	// Sets the ID.
	ID(v string) IStack

	// Sets the class. Multiple classes can be defined 
    
func (s *stack) Render() app.UI {
	body := app.Div().
		DataSet("goapp", "Stack").
		ID(s.Iid).
		Class(s.Iclass).
		Style("display", "flex").
		Style("justify-content", s.IhorizontalAlign).
		Style("align-items", s.IverticalAlign)

	for _, s := range s.Istyles {
		body.Style(s.key, s.value)
	}

	return body.Body(s.Icontent...)
}