func newVBoxLayout(sizes []int) fyne.Layout {
	return &boxLayout{false, sizes}
}
NewVBoxLayout returns a vertical box layout for stacking a number of child
canvas objects or widgets top to bottom.
package main
import (
	"fyne.io/fyne"
	"fyne.io/fyne/layout"
	"fyne.io/fyne/theme"
)
var _ fyne.Layout = (*boxLayout)(nil)
type boxLayout struct {
	horizontal bool
	sizes      []int
}
func newHBoxLayout(sizes []int) fyne.Layout {
	return &boxLayout{true, sizes}
}