如何使用andlabs ui在golang中设置框的长度？

I am making a graphics page using andlabs ui. I want to increase length of seearch box. How can we increase it? How can we increase box length and set box height and width?

package main

import (

    "github.com/andlabs/ui"

)

func main() {

    err := ui.Main(func() {

    hbox := ui.NewHorizontalBox();      

    left_hbox := ui.NewHorizontalBox();
    hbox.Append(left_hbox, true)

    search_vbox := ui.NewVerticalBox()
    hbox.Append(search_vbox, true)

    search_hbox := ui.NewHorizontalBox()
    search_vbox.Append(search_hbox, true)

    search_input := ui.NewEntry();
    search_hbox.Append(search_input, true)

    search_button := ui.NewButton("