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: main.go
    path of file: ./repos/tview/demos/grid
    
    the code of the file until where you have to start completion: // Demo code f
    
func main() {
	newPrimitive := func(text string) tview.Primitive {
		return tview.NewTextView().
			SetTextAlign(tview.AlignCenter).
			SetText(text)
	}
	menu := newPrimitive("Menu")
	main := newPrimitive("Main content")
	sideBar := newPrimitive("Side Bar")

	grid := tview.NewGrid().
		SetRows(3, 0, 3).
		SetColumns(30, 0, 30).
		SetBorders(true).
		AddItem(newPrimitive("Header"), 0, 0, 1, 3, 0, 0, false).
		AddItem(newPrimitive("Footer"), 2, 0, 1, 3, 0, 0, false)

	// Layout for screens narrower than 100 cells (menu and side bar are hidden).
	grid.AddItem(menu, 0, 0, 0, 0, 0, 0, false).
		AddItem(main, 1, 0, 1, 3, 0, 0, false).
		AddItem(sideBar, 0, 0, 0, 0, 0, 0, false)

	// Layout for screens wider than 100 cells.
	grid.AddItem(menu, 1, 0, 1, 1, 0, 100, false).
		AddItem(main, 1, 1, 1, 1, 0, 100, false).
		AddItem(sideBar, 1, 2, 1, 1, 0, 100, false)

	if err := tview.NewApplication().SetRoot(grid, true).EnableMouse(true).Run(); err != nil {
		panic(err)
	}
}