如何删除UIBarButtonItem旁边的填充

let customButton = UIButton(type: .system)
customButton.setImage(UIImage(named: "your_image_name"), for: .normal)
customButton.frame = CGRect(x: 0, y: 0, width: 30, height: 30)
let customBarButtonItem = UIBarButtonItem(customView: customButton)

navigationItem.rightBarButtonItem = customBarButtonItem

navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default)
navigationController?.navigationBar.shadowImage = UIImage()
navigationController?.navigationBar.isTranslucent = false